# Private offline period tracker No account, AI or record uploads. The independent app has no ads or analytics. > Canonical page: https://elysiatools.com/en/tools/private-offline-period-tracker - **Category:** Health - **Keywords:** Private offline period tracker, Calendar, Your records ## Overview ## Private offline period tracker No account, AI or record uploads. The independent app has no ads or analytics. Recording happens in a separate offline-ready page, not in this tool form. This password never leaves your browser. It cannot be reset. Backups need the same password. The notebook locks after 10 minutes of inactivity. Center: median of up to 6 recent intervals. Range: shortest to longest observed interval, not a statistical confidence interval. Future cycles can fall outside it. Turn off estimates during pregnancy, postpartum, breastfeeding, hormonal contraception or when calendar assumptions do not apply. Fertility reference assumes ovulation 14 days before the estimated center, plus the preceding 5 days; it does not confirm ovulation. Calendar estimates cannot detect ovulation, pregnancy or illness. Never use them for contraception. For severe pain, unusually heavy bleeding or concerning changes, seek medical advice. Clearing site data, private browsing or browser cleanup can erase records. This device/browser has its own notebook; there is no cloud sync. Encrypted at rest, not an anonymity guarantee. An unlocked screen, malicious extension, compromised device or compromised site code can expose records. The initial app download still contacts this website. ## When to use - When you want to track menstrual cycle intervals without sending health records to remote cloud servers. - When you need an offline-ready calendar notebook that functions reliably without an active internet connection. - When you prefer local client-side encryption and an automatic 10-minute inactivity lock for sensitive personal notes. ## How it works - Open the standalone, offline-ready notebook page linked directly from the tool overview. - Set a secure personal passphrase that encrypts your cycle logs locally in your browser storage. - Log cycle start dates to view your historical interval range alongside a central median estimate based on up to 6 recent intervals. ## Use cases - Logging period start and end dates privately on a personal device without tracking cookies or advertising scripts. - Reviewing historical cycle length variability to discuss observed patterns during medical consultations. - Managing cycle dates while traveling or working in areas with limited or no internet access. ## Frequently asked questions ### Can I recover my password if I forget it? No. The password never leaves your browser, cannot be reset, and is strictly required to decrypt your notes and backups. ### Are my cycle logs synchronized across my phone and laptop? No. Each browser and device stores its own independent notebook locally without cloud synchronization. ### Can I use the calendar estimates for contraception? No. Calendar calculations assume standard intervals and cannot confirm ovulation, detect pregnancy, or prevent conception. ### Will clearing my browser cache delete my records? Yes. Clearing website data, browsing in private mode, or automated disk cleanup tools can permanently erase your local logs. ### How are cycle predictions calculated? The center uses the median of up to 6 recent intervals, while the range displays your shortest and longest recorded cycles. ## Related tools - [Ovulation Calculator](https://elysiatools.com/en/tools/ovulation-calculator): Calculate ovulation date and fertile window based on menstrual cycle - [Fetal Development Timeline (by Gestational Week)](https://elysiatools.com/en/tools/fetal-development-timeline): See week-by-week fetal development from conception to birth (40 weeks). 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