About the Days Until Calculator
This days-until calculator counts the days left until an event, such as a wedding, vacation, exam or due date, and the days since a date, such as a relationship start, quitting smoking or a sobriety date. Enter a future date to get a countdown with the dates you hit 100, 30 and 7 days to go. Enter a past date to see milestones from 100 days to 10,000 days and anniversaries up to 30 years, with how far away each one is.
How to use
- Enter the date: an upcoming event or the day something started.
- The Count from date is today by default. Change it only to count from another day.
- Turn on Count the start date as day 1 if the first day itself should count (common for baby milestones and relationship anniversaries).
- Check the table below for the next milestone (green badge) and how many days away it is. Your entry is saved in this browser.
Counting the start date or not
There are two ways to count days from a start date. Normal date math counts the day after the start date as day 1, so 100 days later is start date + 100. If the start date itself is day 1 (as many couples and parents count), the 100th day is start date + 99.
| Start: January 1, 2026 | Start = day 1 | Next day = day 1 |
|---|---|---|
| 100 days | April 10, 2026 | April 11, 2026 |
| 1,000 days | September 26, 2028 | September 27, 2028 |
| 1 year | January 1, 2027 | January 1, 2027 |
Anniversaries in years always fall on the same calendar date, whichever method you use.
Popular milestones to celebrate
- 100 days: a classic first milestone for a relationship, a new baby, a new job or a habit streak.
- 1,000 days: roughly 2 years and 9 months.
- 10,000 days: about 27 years and 4 months, a fun “birthday” to celebrate once in a lifetime.
- Anniversaries: the same date every year. If you started on February 29, the anniversary falls on February 28 in common years.
FAQ
How do I count the days until a date?
Enter the date and the calculator subtracts today’s date. Today is not counted, so if the event is tomorrow, it shows 1 day to go.
Is the start date included when counting days since?
By default, no: the day after the start date is day 1. Turn on “Count the start date as day 1” to include it. The result then goes up by one day.
What if my start date is February 29?
In years without February 29, the anniversary is shown on February 28. In leap years it stays on February 29.
Is my date saved?
The name, date and counting option are saved only in this browser so they are there next time. Nothing is sent to a server.