The short answer
Recording a period, editing a date, reading the calendar, adding a note, and calculating predictions all run on the iPhone. The widget reads the same App Group data, and reminders are local notifications scheduled on the device.
Airplane mode therefore does not block those core features. A widget refresh can still be delayed by iOS scheduling, but it does not need to download cycle data from a MiniCycle server.
What works with no connection
The core of the app is fully offline. You can log a period start and end, fix a wrong date, and watch the calendar update. The predictions recalculate on the spot: the next period from your saved start dates, ovulation counted back from it, and the fertile window around that.
Daily notes, the statistics tab, and the home-screen widget all read from the same on-device data, so they behave the same with no signal. Reminders do too, because they are local notifications scheduled on the phone rather than messages pushed from a server. A reminder set for next Tuesday arrives next Tuesday whether or not you have been online since.
Features that use a connection
MiniCycle includes Firebase Analytics for usage measurement. Analytics events can wait while the phone is offline and be delivered after a connection returns; that delivery does not block the calendar.
If you enable iCloud Sync, CloudKit also needs a connection to upload and fetch the private copy in your iCloud account. Local changes still save on the phone while offline, and synchronization can resume later. Installing or updating the app through the App Store also requires a connection.
Offline use is not a backup
Working offline does not change the limits of a date-based prediction. It remains reference information, not contraception, a pregnancy test, or a medical opinion.
Records stored only on the device can be lost if the phone is lost, erased, or the app is deleted. Optional iCloud Sync can keep a private CloudKit copy, but it needs a connection to synchronize and is not an independent archive of every past state.
MiniCycle for iPhone
Try MiniCycle
MiniCycle is built for a clean iPhone period calendar, local records, simple statistics, and a home screen widget.
MiniCycle editorial