fox tools
Date & time · ON DEVICE
Days until calculator (D-Day)
Calculate days until a birthday, holiday or event, or count days since a past date.
Today (device local date):
RESULT
D-Day
Your event is today.
How it works
The countdown uses today’s date in your device’s time zone. Future dates show D−N, past dates show D+N, and today shows D-Day. This is a calendar-day countdown, not a timer measured in hours.
How to use
- Choose the date of your event.
- Check the displayed local date.
- Read the days remaining or elapsed.
Worked examples and common mistakes
If today were December 20, 2026, December 25 would show D−5. On December 25 it shows D-Day; on December 26 the same target shows D+1. This differs from anniversary conventions that count the starting date as day one.
If a countdown looks different while travelling, check the displayed current date and your device time zone first. The target is not saved for your next visit. This tool calculates days; it does not schedule reminders or send notifications.
Frequently asked questions
Why is my countdown different abroad?
Devices in different time zones may have different local dates. The countdown follows the date on your device.
Does the countdown update overnight?
Yes. It updates after local midnight and checks again when you return to the tab.