Web Date Time TypeScript Samples

// Web TypeScript Get Current Time Examples
// Retrieving current date and time in various formats and timezones

// 1. Basic Time Retrieval
class TimeRetriever {
  // Get current date
  static getCurrentDate(): Date {
    return new Date();
  }

  // Get current timestamp
  static getCurrentTimestamp(): number {
    return Date.now();
  }

  // Get current time in milliseconds
  static getCurrentTimeMillis(): number {
    return new Date().getTime();
  }

  // Get current UTC date
  static getCurrentUTCDate(): Date {
    return new Date();
  }

  // Get current ISO string
  static getCurrentISOString(): string {
    return new Date().toISOString();
  }

  // Get current date string
  static getCurrentDateString(): string {
    return new Date().toDateString();
  }

  // Get current time string
  static getCurrentTimeString(): string {
    return new Date().toTimeString();
  }

  // Get current locale string
  static getCurrentLocaleString(locale?: string): string {
    return new Date().toLocaleString(locale);
  }

  // Get current UTC string
  static getCurrentUTCString(): string {
    return new Date().toUTCString();
  }
}

// 2. Time Components Extraction
class TimeComponents {
  // Get year
  static getYear(date: Date = new Date()): number {
    return date.getFullYear();
  }

  // Get month (0-11)
  static getMonth(date: Date = new Date()): number {
    return date.getMonth();
  }

  // Get month name
  static getMonthName(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleString(locale, { month: 'long' });
  }

  // Get day of month
  static getDay(date: Date = new Date()): number {
    return date.getDate();
  }

  // Get day of week (0-6)
  static getDayOfWeek(date: Date = new Date()): number {
    return date.getDay();
  }

  // Get day of week name
  static getDayOfWeekName(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleString(locale, { weekday: 'long' });
  }

  // Get hours
  static getHours(date: Date = new Date()): number {
    return date.getHours();
  }

  // Get minutes
  static getMinutes(date: Date = new Date()): number {
    return date.getMinutes();
  }

  // Get seconds
  static getSeconds(date: Date = new Date()): number {
    return date.getSeconds();
  }

  // Get milliseconds
  static getMilliseconds(date: Date = new Date()): number {
    return date.getMilliseconds();
  }

  // Get all components as object
  static getAllComponents(date: Date = new Date()): {
    year: number;
    month: number;
    day: number;
    hours: number;
    minutes: number;
    seconds: number;
    milliseconds: number;
    dayOfWeek: number;
  } {
    return {
      year: date.getFullYear(),
      month: date.getMonth(),
      day: date.getDate(),
      hours: date.getHours(),
      minutes: date.getMinutes(),
      seconds: date.getSeconds(),
      milliseconds: date.getMilliseconds(),
      dayOfWeek: date.getDay()
    };
  }
}

// 3. UTC Time Components
class UTCTimeComponents {
  // Get UTC year
  static getUTCYear(date: Date = new Date()): number {
    return date.getUTCFullYear();
  }

  // Get UTC month
  static getUTCMonth(date: Date = new Date()): number {
    return date.getUTCMonth();
  }

  // Get UTC day
  static getUTCDay(date: Date = new Date()): number {
    return date.getUTCDate();
  }

  // Get UTC hours
  static getUTCHours(date: Date = new Date()): number {
    return date.getUTCHours();
  }

  // Get UTC minutes
  static getUTCMinutes(date: Date = new Date()): number {
    return date.getUTCMinutes();
  }

  // Get UTC seconds
  static getUTCSeconds(date: Date = new Date()): number {
    return date.getUTCSeconds();
  }

  // Get all UTC components
  static getAllUTCComponents(date: Date = new Date()): {
    year: number;
    month: number;
    day: number;
    hours: number;
    minutes: number;
    seconds: number;
    milliseconds: number;
  } {
    return {
      year: date.getUTCFullYear(),
      month: date.getUTCMonth(),
      day: date.getUTCDate(),
      hours: date.getUTCHours(),
      minutes: date.getUTCMinutes(),
      seconds: date.getUTCSeconds(),
      milliseconds: date.getUTCMilliseconds()
    };
  }
}

// 4. Timezone Information
class TimezoneInfo {
  // Get timezone offset in minutes
  static getTimezoneOffset(date: Date = new Date()): number {
    return date.getTimezoneOffset();
  }

  // Get timezone offset in hours
  static getTimezoneOffsetHours(date: Date = new Date()): number {
    return date.getTimezoneOffset() / 60;
  }

  // Get timezone name
  static getTimezoneName(): string {
    return Intl.DateTimeFormat().resolvedOptions().timeZone;
  }

  // Get local timezone string
  static getLocalTimezoneString(): string {
    const offset = new Date().getTimezoneOffset();
    const hours = Math.abs(Math.floor(offset / 60));
    const minutes = Math.abs(offset % 60);
    const sign = offset <= 0 ? '+' : '-';

    return `UTC${sign}${String(hours).padStart(2, '0')}:${String(minutes).padStart(2, '0')}`;
  }

  // Check if DST is in effect
  static isDST(date: Date = new Date()): boolean {
    const jan = new Date(date.getFullYear(), 0, 1).getTimezoneOffset();
    const jul = new Date(date.getFullYear(), 6, 1).getTimezoneOffset();
    const current = date.getTimezoneOffset();

    return current !== Math.max(jan, jul);
  }
}

// 5. High Resolution Time
class HighResolutionTime {
  // Get high resolution timestamp
  static getHighResolutionTime(): number {
    return performance.now();
  }

  // Measure time elapsed
  static measureTime(callback: () => void): number {
    const start = performance.now();
    callback();
    return performance.now() - start;
  }

  // Measure async time
  static async measureTimeAsync<T>(callback: () => Promise<T>): Promise<{ result: T; elapsed: number }> {
    const start = performance.now();
    const result = await callback();
    const elapsed = performance.now() - start;

    return { result, elapsed };
  }

  // Get time with microsecond precision (if available)
  static getPreciseTime(): { seconds: number; nanos: number } {
    const hrTime = typeof process !== 'undefined' && typeof process.hrtime === 'function'
      ? process.hrtime()
      : undefined;
    if (hrTime) {
      return { seconds: hrTime[0], nanos: hrTime[1] };
    }

    // Fallback for browser
    const now = Date.now();
    return { seconds: Math.floor(now / 1000), nanos: (now % 1000) * 1000000 };
  }
}

// 6. Relative Time
class RelativeTime {
  // Get start of day
  static getStartOfDay(date: Date = new Date()): Date {
    const result = new Date(date);
    result.setHours(0, 0, 0, 0);
    return result;
  }

  // Get end of day
  static getEndOfDay(date: Date = new Date()): Date {
    const result = new Date(date);
    result.setHours(23, 59, 59, 999);
    return result;
  }

  // Get start of week
  static getStartOfWeek(date: Date = new Date()): Date {
    const result = new Date(date);
    const day = result.getDay();
    const diff = result.getDate() - day;
    result.setDate(diff);
    result.setHours(0, 0, 0, 0);
    return result;
  }

  // Get end of week
  static getEndOfWeek(date: Date = new Date()): Date {
    const result = new Date(date);
    const day = result.getDay();
    const diff = result.getDate() - day + 6;
    result.setDate(diff);
    result.setHours(23, 59, 59, 999);
    return result;
  }

  // Get start of month
  static getStartOfMonth(date: Date = new Date()): Date {
    const result = new Date(date);
    result.setDate(1);
    result.setHours(0, 0, 0, 0);
    return result;
  }

  // Get end of month
  static getEndOfMonth(date: Date = new Date()): Date {
    const result = new Date(date);
    result.setMonth(result.getMonth() + 1);
    result.setDate(0);
    result.setHours(23, 59, 59, 999);
    return result;
  }

  // Get start of year
  static getStartOfYear(date: Date = new Date()): Date {
    const result = new Date(date);
    result.setMonth(0, 1);
    result.setHours(0, 0, 0, 0);
    return result;
  }

  // Get end of year
  static getEndOfYear(date: Date = new Date()): Date {
    const result = new Date(date);
    result.setMonth(11, 31);
    result.setHours(23, 59, 59, 999);
    return result;
  }
}

// 7. Time Utilities
class TimeUtilities {
  // Check if date is valid
  static isValid(date: Date): boolean {
    return date instanceof Date && !isNaN(date.getTime());
  }

  // Check if date is today
  static isToday(date: Date): boolean {
    const today = new Date();
    return date.getDate() === today.getDate() &&
           date.getMonth() === today.getMonth() &&
           date.getFullYear() === today.getFullYear();
  }

  // Check if date is in the past
  static isPast(date: Date): boolean {
    return date < new Date();
  }

  // Check if date is in the future
  static isFuture(date: Date): boolean {
    return date > new Date();
  }

  // Get leap year
  static isLeapYear(year: number): boolean {
    return (year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0);
  }

  // Get days in month
  static getDaysInMonth(year: number, month: number): number {
    return new Date(year, month + 1, 0).getDate();
  }

  // Compare two dates
  static compare(date1: Date, date2: Date): number {
    return date1.getTime() - date2.getTime();
  }

  // Get difference in days
  static getDaysDifference(date1: Date, date2: Date): number {
    const oneDay = 24 * 60 * 60 * 1000;
    return Math.round((date1.getTime() - date2.getTime()) / oneDay);
  }

  // Get age from birthdate
  static getAge(birthDate: Date): number {
    const today = new Date();
    let age = today.getFullYear() - birthDate.getFullYear();
    const monthDiff = today.getMonth() - birthDate.getMonth();

    if (monthDiff < 0 || (monthDiff === 0 && today.getDate() < birthDate.getDate())) {
      age--;
    }

    return age;
  }
}

// 8. Time Formatting
class QuickFormatter {
  // Format as YYYY-MM-DD
  static toISODate(date: Date = new Date()): string {
    return date.toISOString().split('T')[0];
  }

  // Format as HH:mm:ss
  static toISOTime(date: Date = new Date()): string {
    return date.toTimeString().split(' ')[0];
  }

  // Format as YYYY-MM-DD HH:mm:ss
  static toISODateTime(date: Date = new Date()): string {
    return date.toISOString().replace('T', ' ').split('.')[0];
  }

  // Format locale date
  static toLocaleDate(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleDateString(locale);
  }

  // Format locale time
  static toLocaleTime(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleTimeString(locale);
  }

  // Format locale datetime
  static toLocaleDateTime(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleString(locale);
  }
}

// Usage Examples
async function demonstrateGetCurrentTime() {
  console.log('=== Web TypeScript Get Current Time Examples ===\n');

  // 1. Basic time retrieval
  console.log('--- 1. Basic Time Retrieval ---');
  const now = TimeRetriever.getCurrentDate();
  console.log(`Current date: ${now}`);
  console.log(`Current timestamp: ${TimeRetriever.getCurrentTimestamp()}`);
  console.log(`Current time millis: ${TimeRetriever.getCurrentTimeMillis()}`);
  console.log(`Current ISO string: ${TimeRetriever.getCurrentISOString()}`);
  console.log(`Current date string: ${TimeRetriever.getCurrentDateString()}`);
  console.log(`Current time string: ${TimeRetriever.getCurrentTimeString()}`);
  console.log(`Current locale string: ${TimeRetriever.getCurrentLocaleString()}`);

  // 2. Time components
  console.log('\n--- 2. Time Components ---');
  console.log(`Year: ${TimeComponents.getYear()}`);
  console.log(`Month: ${TimeComponents.getMonth()}`);
  console.log(`Month name: ${TimeComponents.getMonthName()}`);
  console.log(`Day: ${TimeComponents.getDay()}`);
  console.log(`Day of week: ${TimeComponents.getDayOfWeek()}`);
  console.log(`Day name: ${TimeComponents.getDayOfWeekName()}`);
  console.log(`Hours: ${TimeComponents.getHours()}`);
  console.log(`Minutes: ${TimeComponents.getMinutes()}`);
  console.log(`Seconds: ${TimeComponents.getSeconds()}`);

  const components = TimeComponents.getAllComponents();
  console.log(`All components: ${JSON.stringify(components)}`);

  // 3. UTC components
  console.log('\n--- 3. UTC Components ---');
  console.log(`UTC year: ${UTCTimeComponents.getUTCYear()}`);
  console.log(`UTC month: ${UTCTimeComponents.getUTCMonth()}`);
  console.log(`UTC day: ${UTCTimeComponents.getUTCDay()}`);
  console.log(`UTC hours: ${UTCTimeComponents.getUTCHours()}`);

  // 4. Timezone info
  console.log('\n--- 4. Timezone Info ---');
  console.log(`Timezone offset (minutes): ${TimezoneInfo.getTimezoneOffset()}`);
  console.log(`Timezone offset (hours): ${TimezoneInfo.getTimezoneOffsetHours()}`);
  console.log(`Timezone name: ${TimezoneInfo.getTimezoneName()}`);
  console.log(`Local timezone: ${TimezoneInfo.getLocalTimezoneString()}`);
  console.log(`Is DST: ${TimezoneInfo.isDST()}`);

  // 5. High resolution time
  console.log('\n--- 5. High Resolution Time ---');
  const start = performance.now();
  for (let i = 0; i < 1000; i++) {
    // Some work
  }
  const elapsed = performance.now() - start;
  console.log(`Elapsed time: ${elapsed.toFixed(2)}ms`);

  const measured = HighResolutionTime.measureTime(() => {
    let sum = 0;
    for (let i = 0; i < 10000; i++) {
      sum += i;
    }
  });
  console.log(`Measured time: ${measured.toFixed(2)}ms`);

  // 6. Relative time
  console.log('\n--- 6. Relative Time ---');
  console.log(`Start of day: ${RelativeTime.getStartOfDay()}`);
  console.log(`End of day: ${RelativeTime.getEndOfDay()}`);
  console.log(`Start of week: ${RelativeTime.getStartOfWeek()}`);
  console.log(`End of week: ${RelativeTime.getEndOfWeek()}`);
  console.log(`Start of month: ${RelativeTime.getStartOfMonth()}`);
  console.log(`End of month: ${RelativeTime.getEndOfMonth()}`);

  // 7. Time utilities
  console.log('\n--- 7. Time Utilities ---');
  console.log(`Is today: ${TimeUtilities.isToday(new Date())}`);
  console.log(`Is leap year: ${TimeUtilities.isLeapYear(2024)}`);
  console.log(`Days in Feb 2024: ${TimeUtilities.getDaysInMonth(2024, 1)}`);
  console.log(`Days in Feb 2023: ${TimeUtilities.getDaysInMonth(2023, 1)}`);

  const birthDate = new Date('1990-05-15');
  console.log(`Age from 1990-05-15: ${TimeUtilities.getAge(birthDate)}`);

  // 8. Quick formatting
  console.log('\n--- 8. Quick Formatting ---');
  console.log(`ISO date: ${QuickFormatter.toISODate()}`);
  console.log(`ISO time: ${QuickFormatter.toISOTime()}`);
  console.log(`ISO datetime: ${QuickFormatter.toISODateTime()}`);
  console.log(`Locale date: ${QuickFormatter.toLocaleDate()}`);
  console.log(`Locale time: ${QuickFormatter.toLocaleTime()}`);
  console.log(`Locale datetime: ${QuickFormatter.toLocaleDateTime()}`);

  console.log('\n=== All Get Current Time Examples Completed ===');
}

// Export classes
export { TimeRetriever, TimeComponents, UTCTimeComponents, TimezoneInfo, HighResolutionTime, RelativeTime, TimeUtilities, QuickFormatter };
export { demonstrateGetCurrentTime };

// Web TypeScript Date Time Formatting Examples
// Comprehensive date and time formatting using Intl API and custom formatters

// 1. Basic Formatting
class BasicFormatter {
  // Format to ISO string
  static toISOString(date: Date = new Date()): string {
    return date.toISOString();
  }

  // Format to locale string
  static toLocaleString(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleString(locale);
  }

  // Format to locale date
  static toLocaleDateString(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleDateString(locale);
  }

  // Format to locale time
  static toLocaleTimeString(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleTimeString(locale);
  }

  // Format to UTC string
  static toUTCString(date: Date = new Date()): string {
    return date.toUTCString();
  }

  // Format to date string
  static toDateString(date: Date = new Date()): string {
    return date.toDateString();
  }

  // Format to time string
  static toTimeString(date: Date = new Date()): string {
    return date.toTimeString();
  }
}

// 2. Intl DateTime Format
class IntlFormatter {
  // Format with custom options
  static format(
    date: Date,
    options: Intl.DateTimeFormatOptions,
    locale: string = 'en-US'
  ): string {
    return new Intl.DateTimeFormat(locale, options).format(date);
  }

  // Format date only
  static formatDate(date: Date, locale: string = 'en-US'): string {
    return this.format(date, {
      year: 'numeric',
      month: 'long',
      day: 'numeric'
    }, locale);
  }

  // Format time only
  static formatTime(date: Date, locale: string = 'en-US'): string {
    return this.format(date, {
      hour: '2-digit',
      minute: '2-digit',
      second: '2-digit'
    }, locale);
  }

  // Format full
  static formatFull(date: Date, locale: string = 'en-US'): string {
    return this.format(date, {
      weekday: 'long',
      year: 'numeric',
      month: 'long',
      day: 'numeric',
      hour: '2-digit',
      minute: '2-digit',
      second: '2-digit',
      timeZoneName: 'long'
    }, locale);
  }

  // Format short
  static formatShort(date: Date, locale: string = 'en-US'): string {
    return this.format(date, {
      year: 'numeric',
      month: 'short',
      day: 'numeric'
    }, locale);
  }

  // Format medium
  static formatMedium(date: Date, locale: string = 'en-US'): string {
    return this.format(date, {
      year: 'numeric',
      month: 'short',
      day: 'numeric',
      hour: '2-digit',
      minute: '2-digit'
    }, locale);
  }

  // Format long
  static formatLong(date: Date, locale: string = 'en-US'): string {
    return this.format(date, {
      weekday: 'long',
      year: 'numeric',
      month: 'long',
      day: 'numeric'
    }, locale);
  }
}

// 3. Custom Format Patterns
class CustomFormatter {
  // Format as YYYY-MM-DD
  static formatISODate(date: Date = new Date()): string {
    const year = date.getFullYear();
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const day = String(date.getDate()).padStart(2, '0');

    return `${year}-${month}-${day}`;
  }

  // Format as HH:mm:ss
  static formatISOTime(date: Date = new Date()): string {
    const hours = String(date.getHours()).padStart(2, '0');
    const minutes = String(date.getMinutes()).padStart(2, '0');
    const seconds = String(date.getSeconds()).padStart(2, '0');

    return `${hours}:${minutes}:${seconds}`;
  }

  // Format as YYYY-MM-DD HH:mm:ss
  static formatISODateTime(date: Date = new Date()): string {
    return `${this.formatISODate(date)} ${this.formatISOTime(date)}`;
  }

  // Format as DD/MM/YYYY
  static formatDayMonthYear(date: Date = new Date(), separator: string = '/'): string {
    const day = String(date.getDate()).padStart(2, '0');
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const year = date.getFullYear();

    return `${day}${separator}${month}${separator}${year}`;
  }

  // Format as MM/DD/YYYY
  static formatMonthDayYear(date: Date = new Date(), separator: string = '/'): string {
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const day = String(date.getDate()).padStart(2, '0');
    const year = date.getFullYear();

    return `${month}${separator}${day}${separator}${year}`;
  }

  // Format with month name
  static formatWithMonthName(
    date: Date = new Date(),
    locale: string = 'en-US',
    format: 'short' | 'long' = 'long'
  ): string {
    const month = date.toLocaleString(locale, { month: format });
    const day = date.getDate();
    const year = date.getFullYear();

    return `${month} ${day}, ${year}`;
  }

  // Format with day and month names
  static formatWithDayAndMonthNames(
    date: Date = new Date(),
    locale: string = 'en-US'
  ): string {
    const weekday = date.toLocaleString(locale, { weekday: 'long' });
    const month = date.toLocaleString(locale, { month: 'long' });
    const day = date.getDate();
    const year = date.getFullYear();

    return `${weekday}, ${month} ${day}, ${year}`;
  }

  // Format time with AM/PM
  static formatTime12Hour(date: Date = new Date()): string {
    let hours = date.getHours();
    const minutes = String(date.getMinutes()).padStart(2, '0');
    const seconds = String(date.getSeconds()).padStart(2, '0');
    const ampm = hours >= 12 ? 'PM' : 'AM';

    hours = hours % 12;
    hours = hours ? hours : 12;

    return `${hours}:${minutes}:${seconds} ${ampm}`;
  }

  // Format time in 24-hour format
  static formatTime24Hour(date: Date = new Date()): string {
    const hours = String(date.getHours()).padStart(2, '0');
    const minutes = String(date.getMinutes()).padStart(2, '0');
    const seconds = String(date.getSeconds()).padStart(2, '0');

    return `${hours}:${minutes}:${seconds}`;
  }
}

// 4. Relative Time Formatting
class RelativeTimeFormatter {
  // Format time ago
  static formatTimeAgo(date: Date, locale: string = 'en-US'): string {
    const now = new Date();
    const diff = now.getTime() - date.getTime();
    const seconds = Math.floor(diff / 1000);
    const minutes = Math.floor(seconds / 60);
    const hours = Math.floor(minutes / 60);
    const days = Math.floor(hours / 24);
    const months = Math.floor(days / 30);
    const years = Math.floor(days / 365);

    const rtf = new Intl.RelativeTimeFormat(locale, { numeric: 'auto' });

    if (years > 0) {
      return rtf.format(-years, 'year');
    } else if (months > 0) {
      return rtf.format(-months, 'month');
    } else if (days > 0) {
      return rtf.format(-days, 'day');
    } else if (hours > 0) {
      return rtf.format(-hours, 'hour');
    } else if (minutes > 0) {
      return rtf.format(-minutes, 'minute');
    } else {
      return rtf.format(-seconds, 'second');
    }
  }

  // Format time in
  static formatTimeIn(date: Date, locale: string = 'en-US'): string {
    const now = new Date();
    const diff = date.getTime() - now.getTime();
    const seconds = Math.floor(diff / 1000);
    const minutes = Math.floor(seconds / 60);
    const hours = Math.floor(minutes / 60);
    const days = Math.floor(hours / 24);

    const rtf = new Intl.RelativeTimeFormat(locale, { numeric: 'auto' });

    if (days > 0) {
      return rtf.format(days, 'day');
    } else if (hours > 0) {
      return rtf.format(hours, 'hour');
    } else if (minutes > 0) {
      return rtf.format(minutes, 'minute');
    } else {
      return rtf.format(seconds, 'second');
    }
  }

  // Format duration
  static formatDuration(milliseconds: number, locale: string = 'en-US'): string {
    const seconds = Math.floor(milliseconds / 1000);
    const minutes = Math.floor(seconds / 60);
    const hours = Math.floor(minutes / 60);
    const days = Math.floor(hours / 24);

    const parts: string[] = [];

    if (days > 0) {
      parts.push(`${days}d`);
    }
    if (hours % 24 > 0) {
      parts.push(`${hours % 24}h`);
    }
    if (minutes % 60 > 0) {
      parts.push(`${minutes % 60}m`);
    }
    if (seconds % 60 > 0 || parts.length === 0) {
      parts.push(`${seconds % 60}s`);
    }

    return parts.join(' ');
  }
}

// 5. Specialized Formatters
class SpecializedFormatter {
  // Format for file names
  static forFileName(date: Date = new Date()): string {
    const year = date.getFullYear();
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const day = String(date.getDate()).padStart(2, '0');
    const hours = String(date.getHours()).padStart(2, '0');
    const minutes = String(date.getMinutes()).padStart(2, '0');
    const seconds = String(date.getSeconds()).padStart(2, '0');

    return `${year}${month}${day}_${hours}${minutes}${seconds}`;
  }

  // Format for log messages
  static forLog(date: Date = new Date()): string {
    return date.toISOString();
  }

  // Format for UI display
  static forDisplay(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleString(locale, {
      weekday: 'short',
      year: 'numeric',
      month: 'short',
      day: 'numeric',
      hour: '2-digit',
      minute: '2-digit'
    });
  }

  // Format for calendar
  static forCalendar(date: Date = new Date(), locale: string = 'en-US'): string {
    return date.toLocaleString(locale, {
      weekday: 'long',
      year: 'numeric',
      month: 'long',
      day: 'numeric'
    });
  }

  // Format for timestamp
  static forTimestamp(date: Date = new Date()): string {
    return String(date.getTime());
  }

  // Format for HTTP headers
  static forHTTPHeader(date: Date = new Date()): string {
    return date.toUTCString();
  }
}

// 6. Format Builder
class FormatBuilder {
  private parts: Array<string | number> = [];

  // Add year
  year(format: 'numeric' | '2-digit' = 'numeric'): this {
    this.parts.push(`YYYY${format === '2-digit' : 'YY'}`);
    return this;
  }

  // Add month
  month(format: 'numeric' | '2-digit' | 'short' | 'long' = 'numeric'): this {
    this.parts.push(`MM${format}`);
    return this;
  }

  // Add day
  day(format: 'numeric' | '2-digit' = 'numeric'): this {
    this.parts.push(`DD${format}`);
    return this;
  }

  // Add hour
  hour(format: 'numeric' | '2-digit' = '2-digit'): this {
    this.parts.push(`HH${format}`);
    return this;
  }

  // Add minute
  minute(format: 'numeric' | '2-digit' = '2-digit'): this {
    this.parts.push(`mm${format}`);
    return this;
  }

  // Add second
  second(format: 'numeric' | '2-digit' = '2-digit'): this {
    this.parts.push(`ss${format}`);
    return this;
  }

  // Add separator
  separator(sep: string): this {
    this.parts.push(sep);
    return this;
  }

  // Build format
  build(): (date: Date) => string {
    const pattern = this.parts.join('');
    return (date: Date) => {
      return pattern
        .replace(/YYYY/, String(date.getFullYear()))
        .replace(/YY/, String(date.getFullYear()).slice(-2))
        .replace(/MM2-digit/, String(date.getMonth() + 1).padStart(2, '0'))
        .replace(/MMnumeric/, String(date.getMonth() + 1))
        .replace(/DD2-digit/, String(date.getDate()).padStart(2, '0'))
        .replace(/DDnumeric/, String(date.getDate()))
        .replace(/HH2-digit/, String(date.getHours()).padStart(2, '0'))
        .replace(/HHnumeric/, String(date.getHours()))
        .replace(/mm2-digit/, String(date.getMinutes()).padStart(2, '0'))
        .replace(/mmnumeric/, String(date.getMinutes()))
        .replace(/ss2-digit/, String(date.getSeconds()).padStart(2, '0'))
        .replace(/ssnumeric/, String(date.getSeconds()));
    };
  }
}

// Usage Examples
async function demonstrateDateTimeFormatting() {
  console.log('=== Web TypeScript Date Time Formatting Examples ===\n');

  const date = new Date('2024-01-15T14:30:45Z');

  // 1. Basic formatting
  console.log('--- 1. Basic Formatting ---');
  console.log(`ISO string: ${BasicFormatter.toISOString(date)}`);
  console.log(`Locale string: ${BasicFormatter.toLocaleString(date)}`);
  console.log(`Locale date: ${BasicFormatter.toLocaleDateString(date)}`);
  console.log(`Locale time: ${BasicFormatter.toLocaleTimeString(date)}`);
  console.log(`UTC string: ${BasicFormatter.toUTCString(date)}`);

  // 2. Intl formatting
  console.log('\n--- 2. Intl Formatting ---');
  console.log(`Date only: ${IntlFormatter.formatDate(date)}`);
  console.log(`Time only: ${IntlFormatter.formatTime(date)}`);
  console.log(`Full: ${IntlFormatter.formatFull(date)}`);
  console.log(`Short: ${IntlFormatter.formatShort(date)}`);
  console.log(`Medium: ${IntlFormatter.formatMedium(date)}`);
  console.log(`Long: ${IntlFormatter.formatLong(date)}`);

  // 3. Custom formats
  console.log('\n--- 3. Custom Formats ---');
  console.log(`ISO date: ${CustomFormatter.formatISODate(date)}`);
  console.log(`ISO time: ${CustomFormatter.formatISOTime(date)}`);
  console.log(`ISO datetime: ${CustomFormatter.formatISODateTime(date)}`);
  console.log(`DD/MM/YYYY: ${CustomFormatter.formatDayMonthYear(date)}`);
  console.log(`MM/DD/YYYY: ${CustomFormatter.formatMonthDayYear(date)}`);
  console.log(`Month name: ${CustomFormatter.formatWithMonthName(date)}`);
  console.log(`With day/month names: ${CustomFormatter.formatWithDayAndMonthNames(date)}`);
  console.log(`12-hour time: ${CustomFormatter.formatTime12Hour(date)}`);
  console.log(`24-hour time: ${CustomFormatter.formatTime24Hour(date)}`);

  // 4. Relative time
  console.log('\n--- 4. Relative Time ---');
  const past = new Date();
  past.setMinutes(past.getMinutes() - 5);

  const future = new Date();
  future.setHours(future.getHours() + 2);

  console.log(`5 minutes ago: ${RelativeTimeFormatter.formatTimeAgo(past)}`);
  console.log(`2 hours in future: ${RelativeTimeFormatter.formatTimeIn(future)}`);
  console.log(`Duration (3665000ms): ${RelativeTimeFormatter.formatDuration(3665000)}`);

  // 5. Specialized formats
  console.log('\n--- 5. Specialized Formats ---');
  console.log(`File name: ${SpecializedFormatter.forFileName(date)}`);
  console.log(`Log: ${SpecializedFormatter.forLog(date)}`);
  console.log(`Display: ${SpecializedFormatter.forDisplay(date)}`);
  console.log(`Calendar: ${SpecializedFormatter.forCalendar(date)}`);
  console.log(`Timestamp: ${SpecializedFormatter.forTimestamp(date)}`);

  // 6. Format builder
  console.log('\n--- 6. Format Builder ---');
  const customFormat = new FormatBuilder()
    .year()
    .separator('-')
    .month('2-digit')
    .separator('-')
    .day('2-digit')
    .separator(' ')
    .hour('2-digit')
    .separator(':')
    .minute('2-digit')
    .separator(':')
    .second('2-digit')
    .build();

  console.log(`Custom format: ${customFormat(date)}`);

  // 7. Different locales
  console.log('\n--- 7. Different Locales ---');
  const locales = ['en-US', 'de-DE', 'fr-FR', 'ja-JP', 'zh-CN'];

  for (const locale of locales) {
    console.log(`${locale}: ${IntlFormatter.formatLong(date, locale)}`);
  }

  console.log('\n=== All Date Time Formatting Examples Completed ===');
}

// Export classes
export { BasicFormatter, IntlFormatter, CustomFormatter, RelativeTimeFormatter, SpecializedFormatter, FormatBuilder };
export { demonstrateDateTimeFormatting };

// Web TypeScript Date Time Parsing Examples
// Parse strings into Date objects from various formats and validate date strings

// 1. Basic Parsing
class BasicParser {
  // Parse ISO string
  static parseISO(isoString: string): Date | null {
    const date = new Date(isoString);
    return isNaN(date.getTime()) ? null : date;
  }

  // Parse timestamp
  static parseTimestamp(timestamp: number): Date | null {
    const date = new Date(timestamp);
    return isNaN(date.getTime()) ? null : date;
  }

  // Parse date string (browser implementation)
  static parse(dateString: string): Date | null {
    const date = new Date(dateString);
    return isNaN(date.getTime()) ? null : date;
  }

  // Parse UTC string
  static parseUTC(utcString: string): Date | null {
    const date = new Date(utcString);
    return isNaN(date.getTime()) ? null : date;
  }
}

// 2. Custom Format Parsing
class CustomFormatParser {
  // Parse YYYY-MM-DD
  static parseISODate(dateString: string): Date | null {
    const match = dateString.match(/^(\d{4})-(\d{2})-(\d{2})$/);

    if (!match) {
      return null;
    }

    const [, year, month, day] = match;
    const date = new Date(`${year}-${month}-${day}T00:00:00Z`);

    return isNaN(date.getTime()) ? null : date;
  }

  // Parse DD/MM/YYYY or MM/DD/YYYY
  static parseDelimitedDate(
    dateString: string,
    format: 'DMY' | 'MDY' | 'YMD' = 'DMY'
  ): Date | null {
    const parts = dateString.split(/[\/\-]/);

    if (parts.length !== 3) {
      return null;
    }

    let [p1, p2, p3] = parts.map(p => parseInt(p));

    let year: number, month: number, day: number;

    if (format === 'DMY') {
      day = p1;
      month = p2;
      year = p3;
    } else if (format === 'MDY') {
      month = p1;
      day = p2;
      year = p3;
    } else {
      year = p1;
      month = p2;
      day = p3;
    }

    // Handle 2-digit years
    if (year < 100) {
      year += year < 50 ? 2000 : 1900;
    }

    const date = new Date(year, month - 1, day);

    if (date.getFullYear() !== year ||
        date.getMonth() !== month - 1 ||
        date.getDate() !== day) {
      return null;
    }

    return date;
  }

  // Parse time string HH:mm:ss
  static parseTime(timeString: string, baseDate: Date = new Date()): Date | null {
    const match = timeString.match(/^(\d{2}):(\d{2}):(\d{2})$/);

    if (!match) {
      return null;
    }

    const [, hours, minutes, seconds] = match.map(Number);
    const date = new Date(baseDate);

    date.setHours(hours, minutes, seconds, 0);

    return date;
  }

  // Parse date and time string
  static parseDateTime(dateTimeString: string): Date | null {
    // Try ISO format first
    if (dateTimeString.includes('T')) {
      return BasicParser.parseISO(dateTimeString);
    }

    // Try common formats
    const formats = [
      /^(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})$/,
      /^(\d{2})\/(\d{2})\/(\d{4}) (\d{2}):(\d{2}):(\d{2})$/
    ];

    for (const format of formats) {
      const match = dateTimeString.match(format);

      if (match) {
        const numbers = match.slice(1).map(Number);
        let date: Date;

        if (dateTimeString.includes('-')) {
          // YYYY-MM-DD HH:mm:ss
          date = new Date(numbers[0], numbers[1] - 1, numbers[2], numbers[3], numbers[4], numbers[5]);
        } else {
          // MM/DD/YYYY HH:mm:ss
          date = new Date(numbers[2], numbers[0] - 1, numbers[1], numbers[3], numbers[4], numbers[5]);
        }

        return isNaN(date.getTime()) ? null : date;
      }
    }

    return null;
  }
}

// 3. Natural Language Parsing
class NaturalLanguageParser {
  // Parse relative time strings like "in 5 minutes", "2 hours ago"
  static parseRelative(relativeString: string, baseDate: Date = new Date()): Date | null {
    const now = baseDate;
    const match = relativeString.match(/(in|ago)\s+(\d+)\s+(second|minute|hour|day|week|month|year)s?/i);

    if (!match) {
      return null;
    }

    const [, direction, amount, unit] = match;
    const value = parseInt(amount);

    let milliseconds = 0;

    switch (unit.toLowerCase()) {
      case 'second':
        milliseconds = value * 1000;
        break;
      case 'minute':
        milliseconds = value * 60 * 1000;
        break;
      case 'hour':
        milliseconds = value * 60 * 60 * 1000;
        break;
      case 'day':
        milliseconds = value * 24 * 60 * 60 * 1000;
        break;
      case 'week':
        milliseconds = value * 7 * 24 * 60 * 60 * 1000;
        break;
      case 'month':
        milliseconds = value * 30 * 24 * 60 * 60 * 1000;
        break;
      case 'year':
        milliseconds = value * 365 * 24 * 60 * 60 * 1000;
        break;
    }

    if (direction.toLowerCase() === 'in') {
      return new Date(now.getTime() + milliseconds);
    } else {
      return new Date(now.getTime() - milliseconds);
    }
  }

  // Parse "today", "tomorrow", "yesterday"
  static parseDay(dayString: string, baseDate: Date = new Date()): Date | null {
    const today = new Date(baseDate);
    today.setHours(0, 0, 0, 0);

    switch (dayString.toLowerCase()) {
      case 'today':
        return today;
      case 'tomorrow':
        return new Date(today.getTime() + 24 * 60 * 60 * 1000);
      case 'yesterday':
        return new Date(today.getTime() - 24 * 60 * 60 * 1000);
      default:
        return null;
    }
  }

  // Parse "next week", "last month"
  static parsePeriod(periodString: string, baseDate: Date = new Date()): Date | null {
    const match = periodString.match(/(next|last)\s+(week|month|year)/i);

    if (!match) {
      return null;
    }

    const [, direction, period] = match;
    const now = new Date(baseDate);

    if (period.toLowerCase() === 'week') {
      const days = direction.toLowerCase() === 'next' ? 7 : -7;
      return new Date(now.getTime() + days * 24 * 60 * 60 * 1000);
    } else if (period.toLowerCase() === 'month') {
      const months = direction.toLowerCase() === 'next' ? 1 : -1;
      return new Date(now.getFullYear(), now.getMonth() + months, now.getDate());
    } else if (period.toLowerCase() === 'year') {
      const years = direction.toLowerCase() === 'next' ? 1 : -1;
      return new Date(now.getFullYear() + years, now.getMonth(), now.getDate());
    }

    return null;
  }
}

// 4. Validation
class DateValidator {
  // Check if date string is valid
  static isValid(dateString: string): boolean {
    const date = new Date(dateString);
    return !isNaN(date.getTime());
  }

  // Validate ISO format
  static isValidISO(dateString: string): boolean {
    return /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d+)?(Z|[+-]\d{2}:\d{2})?$/.test(dateString);
  }

  // Validate date format YYYY-MM-DD
  static isValidISODate(dateString: string): boolean {
    if (!/^\d{4}-\d{2}-\d{2}$/.test(dateString)) {
      return false;
    }

    const date = new Date(dateString);
    return !isNaN(date.getTime());
  }

  // Validate time format HH:mm:ss
  static isValidTime(timeString: string): boolean {
    if (!/^\d{2}:\d{2}:\d{2}$/.test(timeString)) {
      return false;
    }

    const [hours, minutes, seconds] = timeString.split(':').map(Number);

    return hours >= 0 && hours <= 23 &&
           minutes >= 0 && minutes <= 59 &&
           seconds >= 0 && seconds <= 59;
  }

  // Validate email-style date
  static isValidEmailDate(dateString: string): boolean {
    return /^w{3},?s+d{1,2}s+w{3}s+d{4}s+d{2}:d{2}:d{2}s+[+-]?d{4}/.test(dateString);
  }
}

// 5. Format Detection
class FormatDetector {
  // Detect date format
  static detectFormat(dateString: string): string | null {
    if (/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}/.test(dateString)) {
      return 'ISO-8601';
    }

    if (/^\d{4}-\d{2}-\d{2}$/.test(dateString)) {
      return 'ISO-Date';
    }

    if (/^\d{2}\/\d{2}\/\d{4}$/.test(dateString)) {
      return 'Delimited';
    }

    if (/^\w{3},\s+\d{1,2}\s+\w{3}\s+\d{4}/.test(dateString)) {
      return 'HTTP-Date';
    }

    return null;
  }
}

// 6. Flexible Parser
class FlexibleParser {
  // Try multiple formats until one works
  static parse(dateString: string): Date | null {
    // Try built-in parsing first
    const builtin = BasicParser.parse(dateString);
    if (builtin) return builtin;

    // Try ISO date
    const isoDate = CustomFormatParser.parseISODate(dateString);
    if (isoDate) return isoDate;

    // Try delimited formats
    const dmy = CustomFormatParser.parseDelimitedDate(dateString, 'DMY');
    if (dmy) return dmy;

    const mdy = CustomFormatParser.parseDelimitedDate(dateString, 'MDY');
    if (mdy) return mdy;

    const ymd = CustomFormatParser.parseDelimitedDate(dateString, 'YMD');
    if (ymd) return ymd;

    // Try natural language
    const relative = NaturalLanguageParser.parseRelative(dateString);
    if (relative) return relative;

    const day = NaturalLanguageParser.parseDay(dateString);
    if (day) return day;

    return null;
  }

  // Parse with fallback
  static parseWithFallback(dateString: string, fallback: Date = new Date()): Date {
    const parsed = this.parse(dateString);
    return parsed || fallback;
  }
}

// 7. Timezone Parsing
class TimezoneParser {
  // Parse with timezone
  static parseWithTimezone(dateString: string, timezone: string): Date | null {
    try {
      const formatter = new Intl.DateTimeFormat('en-US', {
        timeZone: timezone,
        year: 'numeric',
        month: 'numeric',
        day: 'numeric',
        hour: 'numeric',
        minute: 'numeric',
        second: 'numeric'
      });

      const parts = formatter.formatToParts(new Date(dateString));
      const date: any = {};

      for (const part of parts) {
        if (part.type !== 'literal') {
          date[part.type] = part.value;
        }
      }

      return new Date(`${date.year}-${date.month}-${date.day}T${date.hour}:${date.minute}:${date.second}`);
    } catch {
      return null;
    }
  }
}

// Usage Examples
async function demonstrateDateTimeParsing() {
  console.log('=== Web TypeScript Date Time Parsing Examples ===\n');

  // 1. Basic parsing
  console.log('--- 1. Basic Parsing ---');
  console.log(`ISO string: ${BasicParser.parseISO('2024-01-15T10:30:00Z')}`);
  console.log(`Timestamp: ${BasicParser.parseTimestamp(1705318200000)}`);
  console.log(`Date string: ${BasicParser.parse('January 15, 2024')}`);
  console.log(`UTC string: ${BasicParser.parseUTC('Mon, 15 Jan 2024 10:30:00 GMT')}`);

  // 2. Custom format parsing
  console.log('\n--- 2. Custom Format Parsing ---');
  console.log(`ISO date: ${CustomFormatParser.parseISODate('2024-01-15')}`);
  console.log(`DD/MM/YYYY: ${CustomFormatParser.parseDelimitedDate('15/01/2024', 'DMY')}`);
  console.log(`MM/DD/YYYY: ${CustomFormatParser.parseDelimitedDate('01/15/2024', 'MDY')}`);
  console.log(`Time: ${CustomFormatParser.parseTime('14:30:45')}`);
  console.log(`DateTime: ${CustomFormatParser.parseDateTime('2024-01-15 14:30:45')}`);

  // 3. Natural language parsing
  console.log('\n--- 3. Natural Language Parsing ---');
  console.log(`"in 5 minutes": ${NaturalLanguageParser.parseRelative('in 5 minutes')}`);
  console.log(`"2 hours ago": ${NaturalLanguageParser.parseRelative('2 hours ago')}`);
  console.log(`"tomorrow": ${NaturalLanguageParser.parseDay('tomorrow')}`);
  console.log(`"yesterday": ${NaturalLanguageParser.parseDay('yesterday')}`);
  console.log(`"next week": ${NaturalLanguageParser.parsePeriod('next week')}`);
  console.log(`"last month": ${NaturalLanguageParser.parsePeriod('last month')}`);

  // 4. Validation
  console.log('\n--- 4. Validation ---');
  console.log(`"2024-01-15" is valid: ${DateValidator.isValid('2024-01-15')}`);
  console.log(`"2024-01-15T10:30:00Z" is valid ISO: ${DateValidator.isValidISO('2024-01-15T10:30:00Z')}`);
  console.log(`"2024-01-15" is valid ISO date: ${DateValidator.isValidISODate('2024-01-15')}`);
  console.log(`"14:30:45" is valid time: ${DateValidator.isValidTime('14:30:45')}`);
  console.log(`"25:61:61" is valid time: ${DateValidator.isValidTime('25:61:61')}`);

  // 5. Format detection
  console.log('\n--- 5. Format Detection ---');
  const formats = [
    '2024-01-15T10:30:00Z',
    '2024-01-15',
    '01/15/2024',
    'Mon, 15 Jan 2024 10:30:00 GMT'
  ];

  for (const format of formats) {
    console.log(`"${format}" => ${FormatDetector.detectFormat(format)}`);
  }

  // 6. Flexible parsing
  console.log('\n--- 6. Flexible Parsing ---');
  const inputs = [
    '2024-01-15',
    '15/01/2024',
    'January 15, 2024',
    'in 5 minutes',
    'tomorrow',
    'next week',
    'invalid date'
  ];

  for (const input of inputs) {
    const parsed = FlexibleParser.parse(input);
    console.log(`"${input}" => ${parsed || 'null'}`);
  }

  // 7. Parse with fallback
  console.log('\n--- 7. Parse with Fallback ---');
  const fallback = new Date('2020-01-01');
  console.log(`Valid date: ${FlexibleParser.parseWithFallback('2024-01-15', fallback)}`);
  console.log(`Invalid date (fallback): ${FlexibleParser.parseWithFallback('invalid', fallback)}`);

  console.log('\n=== All Date Time Parsing Examples Completed ===');
}

// Export classes
export { BasicParser, CustomFormatParser, NaturalLanguageParser, DateValidator, FormatDetector, FlexibleParser, TimezoneParser };
export { demonstrateDateTimeParsing };