Count days between two dates, until a deadline, or since an anniversary — with share cards.
What is a day counter and countdown?
A day counter calculates the number of days between two dates. A countdown tells you how many days remain until a future date (or how many days have passed since a past date). Together they help you track anniversaries, deadlines, holidays and milestones without manually counting on a calendar.
How days between dates are calculated
The calculation is straightforward calendar arithmetic:
Days = End date − Start date
If the end date is in the future, the result is a positive countdown (days until). If the end date is in the past, we show the absolute value as the number of days since. Leap years are handled automatically — February 29 is counted correctly in leap years.
Common uses
- Anniversaries: "How many days have we been together?" Enter your relationship start date to see the exact count.
- Exam or holiday countdown: Set the end date to your exam or vacation to see how many days remain.
- Project deadlines: Track how many days are left until a deliverable is due.
- Pregnancy due date: Count weeks and days until the expected delivery date (280 days from last menstrual period).
- Visa and travel: Count days remaining on a visa or until a trip begins.
- Retirement countdown: See exactly how many days until your planned retirement date.
Step-by-step: count days or set a countdown
- Pick a start date. For anniversaries, this is the original date. For countdowns, use today (the default).
- Pick an end date. The target date — your anniversary, deadline or holiday.
- Click Calculate. You see the total days, plus weeks, months and hours.
- Copy the share text. Use the "Copy share text" button to get a ready-made message for social media or messaging.
Tips for accurate date counting
- Decide whether to include the end date. Our calculator uses end − start (exclusive of the end date). For inclusive counting (e.g. days including both today and the target), add 1.
- Watch time zones. Date calculations assume your local time zone. For international events, confirm the date in the event's time zone.
- Use the same calendar. Our calculator uses the Gregorian calendar (the international standard). Chinese lunar dates need conversion first.
- Leap years matter. A period spanning February 29 in a leap year will be one day longer. The calculator handles this automatically.
FAQ
How are days between dates counted?
We count the difference between the two calendar dates (end − start). If the end date is before the start date, we show the absolute value as a forward countdown.
What can I use this for?
Anniversaries ("how many days have we been together?"), exam or holiday countdowns, project deadlines, pregnancy due dates, visa days and more.
Is the end date included?
No, we use end − start (exclusive). If you need both endpoints, add 1 day.
Do leap years affect the count?
Yes, but the calculator handles them automatically. A period crossing Feb 29 in a leap year is one day longer.
How many weeks is 100 days?
100 days ≈ 14.29 weeks, or exactly 14 weeks and 2 days.