Plain DatesClear date calculations, with the rules shown.

Date countdown

Count down to a calendar date

See the number of full calendar days until a target date—or how many days have passed—and create an all-day calendar reminder.

Choose a target date

Why calendar days differ from elapsed hours

A countdown to a date usually answers “how many date changes remain?” Subtracting local timestamps can be off by an hour around daylight-saving transitions, so this calculator compares date-only values instead.

Calendar reminder behavior

The ICS file creates one all-day event. In the iCalendar format, an all-day event’s end date is exclusive, so a one-day reminder for December 25 ends on December 26. Import behavior can vary; review the event in your calendar before relying on it.

Limits

The current date comes from your device clock. An incorrect device date produces an incorrect countdown. The file contains the selected date and reminder title only and is generated locally.

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