Exemples de Date et Heure Web Python

# Web Python Get Current Time Examples
# Getting current system time and date with various precision

# 1. Basic Current Time
from datetime import datetime, date, time, timezone
from time import time as time_time, time_ns, ctime, localtime, gmtime, strftime
import time

def get_current_datetime() -> datetime:
    """
    Get current date and time

    Returns:
        Current datetime object
    """
    return datetime.now()

def get_current_date() -> date:
    """
    Get current date only

    Returns:
        Current date object
    """
    return date.today()

def get_current_time() -> time:
    """
    Get current time only

    Returns:
        Current time object
    """
    return datetime.now().time()

def get_current_timestamp() -> float:
    """
    Get current Unix timestamp

    Returns:
        Timestamp as float
    """
    return time.time()

def get_current_timestamp_ns() -> int:
    """
    Get current Unix timestamp in nanoseconds

    Returns:
        Timestamp as integer (nanoseconds)
    """
    return time.time_ns()

# 2. Time with Timezone
def get_utc_now() -> datetime:
    """
    Get current UTC time

    Returns:
        Current UTC datetime
    """
    return datetime.now(timezone.utc)

def get_current_timezone() -> datetime:
    """
    Get current time with local timezone

    Returns:
        Current datetime with local timezone
    """
    return datetime.now().astimezone()

def get_timezone_offset() -> int:
    """
    Get local timezone offset in seconds

    Returns:
        Offset in seconds
    """
    return time.timezone if time.daylight == 0 else time.altzone

def get_timezone_name() -> str:
    """
    Get local timezone name

    Returns:
        Timezone name
    """
    return time.tzname[time.daylight]

# 3. High Precision Time
def get_high_precision_time() -> float:
    """
    Get time with high precision

    Returns:
        Time as float (seconds since epoch)
    """
    return time_time()

def get_monotonic_time() -> float:
    """
    Get monotonic time (cannot go backwards)

    Returns:
        Monotonic clock time
    """
    return time.monotonic()

def get_perf_counter() -> float:
    """
    Get performance counter time (highest resolution)

    Returns:
        Performance counter time
    """
    return time.perf_counter()

def get_process_time() -> float:
    """
    Get process CPU time

    Returns:
        Process CPU time
    """
    return time.process_time()

def get_thread_time() -> float:
    """
    Get thread CPU time

    Returns:
        Thread CPU time
    """
    return time.thread_time()

# 4. Time Components
def get_current_year() -> int:
    """Get current year"""
    return datetime.now().year

def get_current_month() -> int:
    """Get current month (1-12)"""
    return datetime.now().month

def get_current_day() -> int:
    """Get current day of month (1-31)"""
    return datetime.now().day

def get_current_hour() -> int:
    """Get current hour (0-23)"""
    return datetime.now().hour

def get_current_minute() -> int:
    """Get current minute (0-59)"""
    return datetime.now().minute

def get_current_second() -> int:
    """Get current second (0-59)"""
    return datetime.now().second

def get_current_microsecond() -> int:
    """Get current microsecond (0-999999)"""
    return datetime.now().microsecond

def get_time_components() -> dict:
    """
    Get all time components as dictionary

    Returns:
        Dictionary with all components
    """
    now = datetime.now()
    return {
        'year': now.year,
        'month': now.month,
        'day': now.day,
        'hour': now.hour,
        'minute': now.minute,
        'second': now.second,
        'microsecond': now.microsecond,
        'weekday': now.weekday(),
        'iso_weekday': now.isoweekday()
    }

# 5. Week and Day Information
def get_current_weekday() -> int:
    """
    Get current weekday (0=Monday, 6=Sunday)

    Returns:
        Weekday number
    """
    return datetime.now().weekday()

def get_current_iso_weekday() -> int:
    """
    Get current ISO weekday (1=Monday, 7=Sunday)

    Returns:
        ISO weekday number
    """
    return datetime.now().isoweekday()

def get_week_of_year() -> int:
    """
    Get current week of year

    Returns:
        Week number (1-53)
    """
    return datetime.now().isocalendar()[1]

def get_day_of_year() -> int:
    """
    Get current day of year

    Returns:
        Day of year (1-366)
    """
    return datetime.now().timetuple().tm_yday

def get_weekday_name() -> str:
    """
    Get current weekday name

    Returns:
        Weekday name (e.g., 'Monday')
    """
    return datetime.now().strftime('%A')

def get_month_name() -> str:
    """
    Get current month name

    Returns:
        Month name (e.g., 'January')
    """
    return datetime.now().strftime('%B')

def get_weekday_name_abbreviated() -> str:
    """
    Get abbreviated weekday name

    Returns:
        Abbreviated weekday name (e.g., 'Mon')
    """
    return datetime.now().strftime('%a')

def get_month_name_abbreviated() -> str:
    """
    Get abbreviated month name

    Returns:
        Abbreviated month name (e.g., 'Jan')
    """
    return datetime.now().strftime('%b')

# 6. Time Strings
def get_time_string() -> str:
    """
    Get current time as string

    Returns:
        Time string (HH:MM:SS)
    """
    return datetime.now().strftime('%H:%M:%S')

def get_date_string() -> str:
    """
    Get current date as string

    Returns:
        Date string (YYYY-MM-DD)
    """
    return datetime.now().strftime('%Y-%m-%d')

def get_datetime_string() -> str:
    """
    Get current datetime as string

    Returns:
        DateTime string (YYYY-MM-DD HH:MM:SS)
    """
    return datetime.now().strftime('%Y-%m-%d %H:%M:%S')

def get_iso_datetime() -> str:
    """
    Get ISO 8601 formatted datetime

    Returns:
        ISO formatted string
    """
    return datetime.now().isoformat()

def get_ctime_string() -> str:
    """
    Get ctime formatted string

    Returns:
        Ctime string
    """
    return ctime()

def get_custom_format(format_string: str) -> str:
    """
    Get time with custom format

    Args:
        format_string: Format string

    Returns:
        Formatted time string
    """
    return datetime.now().strftime(format_string)

# 7. Relative Time
def get_time_since_epoch() -> float:
    """
    Get seconds since Unix epoch

    Returns:
        Seconds since epoch
    """
    return time.time()

def get_time_until_midnight() -> float:
    """
    Get seconds until midnight

    Returns:
        Seconds until midnight
    """
    now = datetime.now()
    midnight = datetime.now().replace(hour=23, minute=59, second=59)
    return (midnight - now).total_seconds()

def get_time_since_midnight() -> float:
    """
    Get seconds since midnight

    Returns:
        Seconds since midnight
    """
    now = datetime.now()
    midnight = now.replace(hour=0, minute=0, second=0, microsecond=0)
    return (now - midnight).total_seconds()

def get_days_in_month() -> int:
    """
    Get number of days in current month

    Returns:
        Days in month
    """
    from calendar import monthrange
    now = datetime.now()
    return monthrange(now.year, now.month)[1]

def is_leap_year() -> bool:
    """
    Check if current year is leap year

    Returns:
        True if leap year
    """
    from calendar import isleap
    return isleap(datetime.now().year)

# 8. Multiple Time Representations
def get_all_time_formats() -> dict:
    """
    Get time in all common formats

    Returns:
        Dictionary with various formats
    """
    now = datetime.now()
    return {
        'iso': now.isoformat(),
        'timestamp': time.time(),
        'ctime': ctime(),
        'date': get_date_string(),
        'time': get_time_string(),
        'datetime': get_datetime_string(),
        'year': now.year,
        'month': now.month,
        'day': now.day,
        'hour': now.hour,
        'minute': now.minute,
        'second': now.second
    }

# 9. Time Measurements
def measure_time_start() -> float:
    """
    Start time measurement

    Returns:
        Start time
    """
    return time.perf_counter()

def measure_time_end(start_time: float) -> float:
    """
    End time measurement

    Args:
        start_time: Start time from measure_time_start

    Returns:
        Elapsed time in seconds
    """
    return time.perf_counter() - start_time

# Usage Examples
def demonstrate_get_current_time():
    print("=== Web Python Get Current Time Examples ===\n")

    # 1. Basic time
    print("--- 1. Basic Current Time ---")
    print(f"Current datetime: {get_current_datetime()}")
    print(f"Current date: {get_current_date()}")
    print(f"Current time: {get_current_time()}")
    print(f"Unix timestamp: {get_current_timestamp()}")
    print(f"Timestamp (ns): {get_current_timestamp_ns()}")

    # 2. Timezone
    print("\n--- 2. Timezone Information ---")
    print(f"UTC now: {get_utc_now()}")
    print(f"Local timezone: {get_current_timezone()}")
    print(f"Timezone offset: {get_timezone_offset()} seconds")
    print(f"Timezone name: {get_timezone_name()}")

    # 3. High precision
    print("\n--- 3. High Precision Time ---")
    print(f"High precision: {get_high_precision_time()}")
    print(f"Monotonic: {get_monotonic_time()}")
    print(f"Perf counter: {get_perf_counter()}")
    print(f"Process time: {get_process_time()}")

    # 4. Components
    print("\n--- 4. Time Components ---")
    print(f"Time components: {get_time_components()}")

    # 5. Week/Day info
    print("\n--- 5. Week and Day Information ---")
    print(f"Weekday (0=Mon): {get_current_weekday()}")
    print(f"ISO weekday (1=Mon): {get_current_iso_weekday()}")
    print(f"Week of year: {get_week_of_year()}")
    print(f"Day of year: {get_day_of_year()}")
    print(f"Weekday name: {get_weekday_name()}")
    print(f"Month name: {get_month_name()}")

    # 6. String formats
    print("\n--- 6. String Formats ---")
    print(f"Time string: {get_time_string()}")
    print(f"Date string: {get_date_string()}")
    print(f"DateTime string: {get_datetime_string()}")
    print(f"ISO format: {get_iso_datetime()}")
    print(f"Custom format: {get_custom_format('%d/%m/%Y %H:%M')}")

    # 7. Relative time
    print("\n--- 7. Relative Time ---")
    print(f"Until midnight: {get_time_until_midnight():.0f} seconds")
    print(f"Since midnight: {get_time_since_midnight():.0f} seconds")
    print(f"Days in month: {get_days_in_month()}")
    print(f"Is leap year: {is_leap_year()}")

    # 8. All formats
    print("\n--- 8. All Formats ---")
    all_formats = get_all_time_formats()
    for key, value in all_formats.items():
        print(f"{key}: {value}")

    # 9. Time measurement
    print("\n--- 9. Time Measurement ---")
    start = measure_time_start()
    time.sleep(0.1)  # Simulate work
    elapsed = measure_time_end(start)
    print(f"Elapsed time: {elapsed:.3f} seconds")

    print("\n=== All Get Current Time Examples Completed ===")

# Export functions
export { get_current_datetime, get_current_date, get_current_time }
export { get_current_timestamp, get_current_timestamp_ns }
export { get_utc_now, get_current_timezone, get_timezone_offset, get_timezone_name }
export { get_high_precision_time, get_monotonic_time, get_perf_counter }
export { get_process_time, get_thread_time }
export { get_current_year, get_current_month, get_current_day }
export { get_current_hour, get_current_minute, get_current_second, get_current_microsecond }
export { get_time_components }
export { get_current_weekday, get_current_iso_weekday, get_week_of_year, get_day_of_year }
export { get_weekday_name, get_month_name, get_weekday_name_abbreviated, get_month_name_abbreviated }
export { get_time_string, get_date_string, get_datetime_string, get_iso_datetime }
export { get_ctime_string, get_custom_format }
export { get_time_since_epoch, get_time_until_midnight, get_time_since_midnight }
export { get_days_in_month, is_leap_year }
export { get_all_time_formats }
export { measure_time_start, measure_time_end }
export { demonstrate_get_current_time }

# Web Python Time Formatting Examples
# Converting datetime objects to formatted strings

# 1. Standard Format Codes
from datetime import datetime, date, time
from typing import Optional

def format_year(dt: datetime) -> str:
    """Format year (YYYY or YY)"""
    return {
        'full': dt.strftime('%Y'),
        'short': dt.strftime('%y'),
        'iso': dt.isoformat()
    }

def format_month(dt: datetime) -> dict:
    """
    Format month in various ways

    Args:
        dt: Datetime object

    Returns:
        Dictionary with various formats
    """
    return {
        'numeric': dt.strftime('%m'),
        'numeric_zero': dt.strftime('%-m'),
        'name': dt.strftime('%B'),
        'name_abbrev': dt.strftime('%b')
    }

def format_day(dt: datetime) -> dict:
    """
    Format day in various ways

    Args:
        dt: Datetime object

    Returns:
        Dictionary with various formats
    """
    return {
        'numeric': dt.strftime('%d'),
        'numeric_space': dt.strftime('%e'),
        'with_ordinal': str(dt.day) + ('th' if 11 <= dt.day <= 13 else {1:'st', 2:'nd', 3:'rd'}.get(dt.day % 10, 'th')),
        'name': dt.strftime('%A'),
        'name_abbrev': dt.strftime('%a')
    }

def format_time(dt: datetime) -> dict:
    """
    Format time in various ways

    Args:
        dt: Datetime object

    Returns:
        Dictionary with various formats
    """
    return {
        '24h': dt.strftime('%H:%M:%S'),
        '12h': dt.strftime('%I:%M:%S %p'),
        '24h_short': dt.strftime('%H:%M'),
        '12h_short': dt.strftime('%I:%M %p'),
        'hour_24': dt.strftime('%H'),
        'hour_12': dt.strftime('%I'),
        'minute': dt.strftime('%M'),
        'second': dt.strftime('%S'),
        'period': dt.strftime('%p')
    }

# 2. Common Date Formats
def format_iso8601(dt: datetime) -> str:
    """
    Format as ISO 8601

    Args:
        dt: Datetime object

    Returns:
        ISO 8601 string
    """
    return dt.isoformat()

def format_rfc2822(dt: datetime) -> str:
    """
    Format as RFC 2822 (email format)

    Args:
        dt: Datetime object

    Returns:
        RFC 2822 string
    """
    return dt.strftime('%a, %d %b %Y %H:%M:%S %z')

def format_rfc3339(dt: datetime) -> str:
    """
    Format as RFC 3339

    Args:
        dt: Datetime object

    Returns:
        RFC 3339 string
    """
    return dt.strftime('%Y-%m-%dT%H:%M:%S%z')

def format_http_date(dt: datetime) -> str:
    """
    Format as HTTP date

    Args:
        dt: Datetime object

    Returns:
        HTTP date string
    """
    return dt.strftime('%a, %d %b %Y %H:%M:%S GMT')

# 3. Regional Formats
def format_us_date(dt: datetime) -> str:
    """
    Format as US date (MM/DD/YYYY)

    Args:
        dt: Datetime object

    Returns:
        US format date
    """
    return dt.strftime('%m/%d/%Y')

def format_eu_date(dt: datetime) -> str:
    """
    Format as European date (DD/MM/YYYY)

    Args:
        dt: Datetime object

    Returns:
        European format date
    """
    return dt.strftime('%d/%m/%Y')

def format_iso_date(dt: datetime) -> str:
    """
    Format as ISO date (YYYY-MM-DD)

    Args:
        dt: Datetime object

    Returns:
        ISO format date
    """
    return dt.strftime('%Y-%m-%d')

def format_chinese_date(dt: datetime) -> str:
    """
    Format as Chinese date (YYYY年MM月DD日)

    Args:
        dt: Datetime object

    Returns:
        Chinese format date
    """
    return dt.strftime('%Y年%m月%d日')

def format_japanese_date(dt: datetime) -> str:
    """
    Format as Japanese date (YYYY年MM月DD日)

    Args:
        dt: Datetime object

    Returns:
        Japanese format date
    """
    return dt.strftime('%Y年%m月%d日')

# 4. Custom Formats
def format_readable(dt: datetime) -> str:
    """
    Format in human-readable form

    Args:
        dt: Datetime object

    Returns:
        Readable string
    """
    return dt.strftime('%A, %B %d, %Y at %I:%M %p')

def format_compact(dt: datetime) -> str:
    """
    Format in compact form

    Args:
        dt: Datetime object

    Returns:
        Compact string
    """
    return dt.strftime('%Y%m%d_%H%M%S')

def format_with_timezone(dt: datetime) -> str:
    """
    Format with timezone info

    Args:
        dt: Datetime object

    Returns:
        String with timezone
    """
    return dt.strftime('%Y-%m-%d %H:%M:%S %Z')

def format_friendly(dt: datetime) -> str:
    """
    Format in friendly form

    Args:
        dt: Datetime object

    Returns:
        Friendly string
    """
    now = datetime.now()
    diff = (now - dt).total_seconds()

    if diff < 60:
        return 'just now'
    elif diff < 3600:
        minutes = int(diff / 60)
        return f'{minutes} minute{"s" if minutes > 1 else ""} ago'
    elif diff < 86400:
        hours = int(diff / 3600)
        return f'{hours} hour{"s" if hours > 1 else ""} ago'
    elif diff < 604800:
        days = int(diff / 86400)
        return f'{days} day{"s" if days > 1 else ""} ago'
    else:
        return dt.strftime('%Y-%m-%d')

# 5. Time Formatting
def format_duration(seconds: float) -> str:
    """
    Format duration in human-readable form

    Args:
        seconds: Duration in seconds

    Returns:
        Formatted duration
    """
    hours = int(seconds // 3600)
    minutes = int((seconds % 3600) // 60)
    secs = int(seconds % 60)

    if hours > 0:
        return f'{hours}h {minutes}m {secs}s'
    elif minutes > 0:
        return f'{minutes}m {secs}s'
    else:
        return f'{secs}s'

def format_duration_precise(seconds: float) -> str:
    """
    Format duration with milliseconds

    Args:
        seconds: Duration in seconds

    Returns:
        Formatted duration with ms
    """
    hours = int(seconds // 3600)
    minutes = int((seconds % 3600) // 60)
    secs = int(seconds % 60)
    millis = int((seconds % 1) * 1000)

    if hours > 0:
        return f'{hours}h {minutes}m {secs}s {millis}ms'
    elif minutes > 0:
        return f'{minutes}m {secs}s {millis}ms'
    else:
        return f'{secs}s {millis}ms'

# 6. Relative Formatting
def format_relative_to_now(dt: datetime) -> str:
    """
    Format datetime relative to now

    Args:
        dt: Datetime object

    Returns:
        Relative time string
    """
    now = datetime.now()
    diff = dt - now if dt > now else now - dt
    seconds = diff.total_seconds()
    future = dt > now

    if seconds < 60:
        amount = int(seconds)
        unit = 'second'
    elif seconds < 3600:
        amount = int(seconds / 60)
        unit = 'minute'
    elif seconds < 86400:
        amount = int(seconds / 3600)
        unit = 'hour'
    elif seconds < 2592000:
        amount = int(seconds / 86400)
        unit = 'day'
    elif seconds < 31536000:
        amount = int(seconds / 2592000)
        unit = 'month'
    else:
        amount = int(seconds / 31536000)
        unit = 'year'

    plural = 's' if amount > 1 else ''
    direction = 'in' if future else 'ago'
    return f'{amount} {unit}{plural} {direction}'

# 7. Business Date Formats
def format_quarter(dt: datetime) -> str:
    """
    Format as quarter

    Args:
        dt: Datetime object

    Returns:
        Quarter string
    """
    quarter = (dt.month - 1) // 3 + 1
    return f'Q{quarter} {dt.year}'

def format_week_number(dt: datetime) -> str:
    """
    Format with week number

    Args:
        dt: Datetime object

    Returns:
        Week string
    """
    return dt.strftime('%Y-W%W')

def format_day_of_year(dt: datetime) -> str:
    """
    Format with day of year

    Args:
        dt: Datetime object

    Returns:
        Day of year string
    """
    return dt.strftime(f'%Y-{dt.timetuple().tm_yday:03d}')

# 8. Locale-Aware Formatting
def format_with_locale(dt: datetime, locale: str = 'en_US') -> str:
    """
    Format using locale settings

    Args:
        dt: Datetime object
        locale: Locale string

    Returns:
        Localized format
    """
    import locale
    try:
        locale.setlocale(locale.LC_TIME, locale)
        formatted = dt.strftime('%c')
        locale.setlocale(locale.LC_TIME, '')  # Reset
        return formatted
    except:
        return dt.strftime('%c')

# 9. Format Validation
def validate_format(format_string: str) -> bool:
    """
    Validate format string

    Args:
        format_string: Format string to validate

    Returns:
        True if valid
    """
    try:
        datetime.now().strftime(format_string)
        return True
    except:
        return False

def get_all_format_codes() -> dict:
    """
    Get all format codes with examples

    Returns:
        Dictionary of format codes
    """
    now = datetime(2025, 12, 31, 14, 30, 45)
    return {
        'Year': {
            '%Y': now.strftime('%Y'),  # 2025
            '%y': now.strftime('%y')   # 25
        },
        'Month': {
            '%m': now.strftime('%m'),  # 12
            '%B': now.strftime('%B'),  # December
            '%b': now.strftime('%b'),  # Dec
        },
        'Day': {
            '%d': now.strftime('%d'),  # 31
            '%A': now.strftime('%A'),  # Wednesday
            '%a': now.strftime('%a'),  # Wed
        },
        'Time': {
            '%H': now.strftime('%H'),  # 14
            '%I': now.strftime('%I'),  # 02
            '%M': now.strftime('%M'),  # 30
            '%S': now.strftime('%S'),  # 45
            '%p': now.strftime('%p'),  # PM
        }
    }

# Usage Examples
def demonstrate_time_formatting():
    print("=== Web Python Time Formatting Examples ===\n")

    now = datetime.now()

    # 1. Standard formats
    print("--- 1. Standard Format Codes ---")
    print(f"Month formats: {format_month(now)}")
    print(f"Day formats: {format_day(now)}")
    print(f"Time formats: {format_time(now)}")

    # 2. Common formats
    print("\n--- 2. Common Date Formats ---")
    print(f"ISO 8601: {format_iso8601(now)}")
    print(f"RFC 2822: {format_rfc2822(now)}")
    print(f"RFC 3339: {format_rfc3339(now)}")
    print(f"HTTP date: {format_http_date(now)}")

    # 3. Regional formats
    print("\n--- 3. Regional Formats ---")
    print(f"US: {format_us_date(now)}")
    print(f"EU: {format_eu_date(now)}")
    print(f"ISO: {format_iso_date(now)}")
    print(f"Chinese: {format_chinese_date(now)}")
    print(f"Japanese: {format_japanese_date(now)}")

    # 4. Custom formats
    print("\n--- 4. Custom Formats ---")
    print(f"Readable: {format_readable(now)}")
    print(f"Compact: {format_compact(now)}")
    print(f"With timezone: {format_with_timezone(now)}")
    print(f"Friendly: {format_friendly(now)}")

    # 5. Duration formatting
    print("\n--- 5. Duration Formatting ---")
    print(f"3661 seconds: {format_duration(3661)}")
    print(f"123.456 seconds: {format_duration_precise(123.456)}")

    # 6. Relative formatting
    print("\n--- 6. Relative Formatting ---")
    future = datetime(2025, 12, 31, 23, 59, 59)
    print(f"Relative to future: {format_relative_to_now(future)}")
    past = datetime(2025, 1, 1, 0, 0, 0)
    print(f"Relative to past: {format_relative_to_now(past)}")

    # 7. Business formats
    print("\n--- 7. Business Date Formats ---")
    print(f"Quarter: {format_quarter(now)}")
    print(f"Week number: {format_week_number(now)}")
    print(f"Day of year: {format_day_of_year(now)}")

    # 8. Format codes reference
    print("\n--- 8. Format Codes Reference ---")
    codes = get_all_format_codes()
    for category, items in codes.items():
        print(f"\n{category}:")
        for code, example in items.items():
            print(f"  {code}: {example}")

    print("\n=== All Time Formatting Examples Completed ===")

# Export functions
export { format_year, format_month, format_day, format_time }
export { format_iso8601, format_rfc2822, format_rfc3339, format_http_date }
export { format_us_date, format_eu_date, format_iso_date, format_chinese_date, format_japanese_date }
export { format_readable, format_compact, format_with_timezone, format_friendly }
export { format_duration, format_duration_precise }
export { format_relative_to_now }
export { format_quarter, format_week_number, format_day_of_year }
export { format_with_locale }
export { validate_format, get_all_format_codes }
export { demonstrate_time_formatting }

# Web Python Time Parsing Examples
# Converting strings to datetime objects with various formats

# 1. Basic Parsing
from datetime import datetime
from typing import Optional, List
import re

def parse_iso8601(date_string: str) -> Optional[datetime]:
    """
    Parse ISO 8601 format

    Args:
        date_string: ISO format string

    Returns:
        Datetime object or None
    """
    try:
        return datetime.fromisoformat(date_string)
    except:
        return None

def parse_rfc2822(date_string: str) -> Optional[datetime]:
    """
    Parse RFC 2822 format

    Args:
        date_string: RFC 2822 format string

    Returns:
        Datetime object or None
    """
    try:
        from email.utils import parsedate_to_datetime
        return parsedate_to_datetime(date_string)
    except:
        return None

def parse_custom_format(date_string: str, format_string: str) -> Optional[datetime]:
    """
    Parse using custom format

    Args:
        date_string: Date string
        format_string: Format string

    Returns:
        Datetime object or None
    """
    try:
        return datetime.strptime(date_string, format_string)
    except:
        return None

# 2. Common Format Parsing
def parse_us_date(date_string: str) -> Optional[datetime]:
    """
    Parse US date (MM/DD/YYYY)

    Args:
        date_string: US format date

    Returns:
        Datetime object or None
    """
    formats = [
        '%m/%d/%Y',
        '%m/%d/%y',
        '%m-%d-%Y',
        '%m-%d-%y'
    ]
    for fmt in formats:
        result = parse_custom_format(date_string, fmt)
        if result:
            return result
    return None

def parse_eu_date(date_string: str) -> Optional[datetime]:
    """
    Parse European date (DD/MM/YYYY)

    Args:
        date_string: EU format date

    Returns:
        Datetime object or None
    """
    formats = [
        '%d/%m/%Y',
        '%d/%m/%y',
        '%d-%m-%Y',
        '%d-%m-%y'
    ]
    for fmt in formats:
        result = parse_custom_format(date_string, fmt)
        if result:
            return result
    return None

def parse_iso_date(date_string: str) -> Optional[datetime]:
    """
    Parse ISO date (YYYY-MM-DD)

    Args:
        date_string: ISO format date

    Returns:
        Datetime object or None
    """
    formats = [
        '%Y-%m-%d',
        '%Y%m%d',
        '%Y-%m-%d %H:%M:%S',
        '%Y-%m-%dT%H:%M:%S'
    ]
    for fmt in formats:
        result = parse_custom_format(date_string, fmt)
        if result:
            return result
    return None

# 3. Flexible Parsing
def parse_auto(date_string: str) -> Optional[datetime]:
    """
    Auto-detect and parse format

    Args:
        date_string: Date string

    Returns:
        Datetime object or None
    """
    # Try ISO 8601 first
    result = parse_iso8601(date_string)
    if result:
        return result

    # Try RFC 2822
    result = parse_rfc2822(date_string)
    if result:
        return result

    # Try common formats
    formats = [
        '%Y-%m-%d %H:%M:%S',
        '%Y-%m-%dT%H:%M:%S',
        '%Y-%m-%d',
        '%d/%m/%Y',
        '%m/%d/%Y',
        '%d.%m.%Y',
        '%m.%d.%Y',
        '%d %b %Y',
        '%d %B %Y',
        '%b %d, %Y',
        '%B %d, %Y',
        '%Y%m%d',
        '%d/%m/%y',
        '%m/%d/%y'
    ]

    for fmt in formats:
        try:
            return datetime.strptime(date_string, fmt)
        except:
            continue

    return None

def parse_auto_list(date_string: str) -> List[datetime]:
    """
    Parse and return all possible interpretations

    Args:
        date_string: Date string

    Returns:
        List of possible datetimes
    """
    results = []
    formats = [
        '%Y-%m-%d %H:%M:%S',
        '%Y-%m-%d',
        '%d/%m/%Y',
        '%m/%d/%Y',
        '%d.%m.%Y',
        '%m.%d.%Y'
    ]

    for fmt in formats:
        try:
            results.append(datetime.strptime(date_string, fmt))
        except:
            continue

    return results

# 4. Time Parsing
def parse_time(time_string: str) -> Optional[datetime]:
    """
    Parse time string

    Args:
        time_string: Time string

    Returns:
        Datetime object or None
    """
    formats = [
        '%H:%M:%S',
        '%H:%M',
        '%I:%M:%S %p',
        '%I:%M %p',
        '%H:%M:%S.%f',
        '%I:%M:%S.%f %p'
    ]

    for fmt in formats:
        try:
            parsed = datetime.strptime(time_string, fmt)
            return parsed
        except:
            continue

    return None

def parse_timestamp(timestamp: float) -> datetime:
    """
    Parse Unix timestamp

    Args:
        timestamp: Unix timestamp

    Returns:
        Datetime object
    """
    return datetime.fromtimestamp(timestamp)

def parse_timestamp_ms(timestamp: int) -> datetime:
    """
    Parse millisecond timestamp

    Args:
        timestamp: Millisecond timestamp

    Returns:
        Datetime object
    """
    return datetime.fromtimestamp(timestamp / 1000)

# 5. Relative Time Parsing
def parse_relative(relative_string: str) -> Optional[datetime]:
    """
    Parse relative time strings

    Args:
        relative_string: Relative time (e.g., "in 5 minutes", "2 hours ago")

    Returns:
        Datetime object or None
    """
    from datetime import timedelta
    import re

    now = datetime.now()

    # Match patterns like "5 minutes ago", "in 2 hours", etc.
    patterns = [
        (r'(\d+)\s+second[s]?\s+ago', lambda m: now - timedelta(seconds=int(m.group(1)))),
        (r'(\d+)\s+minute[s]?\s+ago', lambda m: now - timedelta(minutes=int(m.group(1)))),
        (r'(\d+)\s+hour[s]?\s+ago', lambda m: now - timedelta(hours=int(m.group(1)))),
        (r'(\d+)\s+day[s]?\s+ago', lambda m: now - timedelta(days=int(m.group(1)))),
        (r'\s+in\s+(\d+)\s+second[s]?', lambda m: now + timedelta(seconds=int(m.group(1)))),
        (r'\s+in\s+(\d+)\s+minute[s]?', lambda m: now + timedelta(minutes=int(m.group(1)))),
        (r'\s+in\s+(\d+)\s+hour[s]?', lambda m: now + timedelta(hours=int(m.group(1)))),
        (r'\s+in\s+(\d+)\s+day[s]?', lambda m: now + timedelta(days=int(m.group(1)))),
    ]

    for pattern, calculator in patterns:
        match = re.search(pattern, relative_string, re.IGNORECASE)
        if match:
            return calculator(match)

    return None

# 6. Multi-Format Parsing
def try_multiple_formats(date_string: str, formats: List[str]) -> Optional[datetime]:
    """
    Try multiple formats

    Args:
        date_string: Date string
        formats: List of format strings

    Returns:
        First successful parse or None
    """
    for fmt in formats:
        try:
            return datetime.strptime(date_string, fmt)
        except:
            continue
    return None

# 7. Parser with Fallback
def parse_with_fallback(date_string: str, fallback: Optional[datetime] = None) -> Optional[datetime]:
    """
    Parse with fallback on failure

    Args:
        date_string: Date string
        fallback: Fallback datetime

    Returns:
        Parsed datetime or fallback
    """
    result = parse_auto(date_string)
    return result if result else fallback

# 8. Validation
def is_valid_date(date_string: str, format_string: str) -> bool:
    """
    Validate date string against format

    Args:
        date_string: Date string
        format_string: Format string

    Returns:
        True if valid
    """
    try:
        datetime.strptime(date_string, format_string)
        return True
    except:
        return False

def get_detected_format(date_string: str) -> Optional[str]:
    """
    Detect which format matches

    Args:
        date_string: Date string

    Returns:
        Format string or None
    """
    formats = [
        '%Y-%m-%d',
        '%d/%m/%Y',
        '%m/%d/%Y',
        '%Y-%m-%d %H:%M:%S',
        '%Y-%m-%dT%H:%M:%S',
        '%d %b %Y',
        '%b %d, %Y'
    ]

    for fmt in formats:
        if is_valid_date(date_string, fmt):
            return fmt

    return None

# 9. Extract Date Parts
def extract_date_parts(date_string: str) -> Optional[dict]:
    """
    Extract date parts using regex

    Args:
        date_string: Date string

    Returns:
        Dictionary with parts or None
    """
    # Try ISO format
    match = re.match(r'(\d{4})-(\d{2})-(\d{2})', date_string)
    if match:
        return {
            'year': int(match.group(1)),
            'month': int(match.group(2)),
            'day': int(match.group(3))
        }

    # Try US format
    match = re.match(r'(\d{2})/(\d{2})/(\d{4})', date_string)
    if match:
        return {
            'month': int(match.group(1)),
            'day': int(match.group(2)),
            'year': int(match.group(3))
        }

    # Try EU format
    match = re.match(r'(\d{2})/(\d{2})/(\d{4})', date_string)
    if match:
        return {
            'day': int(match.group(1)),
            'month': int(match.group(2)),
            'year': int(match.group(3))
        }

    return None

# Usage Examples
def demonstrate_time_parsing():
    print("=== Web Python Time Parsing Examples ===\n")

    # 1. Basic parsing
    print("--- 1. Basic Parsing ---")
    iso = "2025-12-31T14:30:45"
    print(f"ISO string: {iso}")
    print(f"Parsed: {parse_iso8601(iso)}")

    custom = "31/12/2025"
    format = "%d/%m/%Y"
    print(f"\nCustom: {custom} with format {format}")
    print(f"Parsed: {parse_custom_format(custom, format)}")

    # 2. Common formats
    print("\n--- 2. Common Format Parsing ---")
    us = "12/31/2025"
    print(f"US date '{us}': {parse_us_date(us)}")

    eu = "31/12/2025"
    print(f"EU date '{eu}': {parse_eu_date(eu)}")

    iso = "2025-12-31"
    print(f"ISO date '{iso}': {parse_iso_date(iso)}")

    # 3. Auto-detect
    print("\n--- 3. Auto-Detection ---")
    test_dates = ["2025-12-31", "31/12/2025", "12/31/2025", "Dec 31, 2025"]
    for date in test_dates:
        parsed = parse_auto(date)
        print(f"'{date}' -> {parsed}")

    # 4. Time parsing
    print("\n--- 4. Time Parsing ---")
    times = ["14:30:45", "2:30 PM", "14:30"]
    for t in times:
        parsed = parse_time(t)
        print(f"'{t}' -> {parsed}")

    # 5. Timestamp parsing
    print("\n--- 5. Timestamp Parsing ---")
    ts = 1735667445
    print(f"Timestamp {ts}: {parse_timestamp(ts)}")

    # 6. Relative time
    print("\n--- 6. Relative Time Parsing ---")
    relative = ["in 5 minutes", "2 hours ago", "3 days ago"]
    for rel in relative:
        parsed = parse_relative(rel)
        print(f"'{rel}' -> {parsed}")

    # 7. Multi-format
    print("\n--- 7. Try Multiple Formats ---")
    formats = ['%Y-%m-%d', '%d/%m/%Y', '%m/%d/%Y']
    result = try_multiple_formats("2025-12-31", formats)
    print(f"Result: {result}")

    # 8. Validation
    print("\n--- 8. Validation ---")
    valid = is_valid_date("2025-12-31", "%Y-%m-%d")
    print(f"Is '2025-12-31' valid for '%Y-%m-%d': {valid}")

    invalid = is_valid_date("31-12-2025", "%Y-%m-%d")
    print(f"Is '31-12-2025' valid for '%Y-%m-%d': {invalid}")

    # 9. Format detection
    print("\n--- 9. Format Detection ---")
    test = "31/12/2025"
    detected = get_detected_format(test)
    print(f"Detected format for '{test}': {detected}")

    # 10. Extract parts
    print("\n--- 10. Extract Date Parts ---")
    parts = extract_date_parts("2025-12-31")
    print(f"Parts: {parts}")

    print("\n=== All Time Parsing Examples Completed ===")

# Export functions
export { parse_iso8601, parse_rfc2822, parse_custom_format }
export { parse_us_date, parse_eu_date, parse_iso_date }
export { parse_auto, parse_auto_list }
export { parse_time, parse_timestamp, parse_timestamp_ms }
export { parse_relative }
export { try_multiple_formats }
export { parse_with_fallback }
export { is_valid_date, get_detected_format }
export { extract_date_parts }
export { demonstrate_time_parsing }