Days Until / Since Calculator
See how many calendar days remain before an event, or how many have passed since it happened.
Choose an event date
Your dates stay in this browser. They are not sent to our server or saved.
Your result
A simple date difference
Enter the date and choose Days until or Days since. An optional event name helps identify the result and stays only in this page.
From 1 January to 10 January, 9 days pass. The event date and today's date being the same gives 0 days. This tool does not count the start date as day one.
Plan with calendar days
All days count, including weekends and holidays. The calculation uses calendar dates, not 24-hour periods measured from a particular time.
If an event is already past, the result reports days elapsed. If it is in the future, it reports days remaining, even when you selected the opposite mode.
Frequently asked questions
Is this a business-day calculator?
No. It counts every calendar day and does not exclude public holidays or weekends.
Can I calculate days since a past date?
Yes. Select Days since and enter the date. The result shows the number of calendar days elapsed.
Can I count the start date as day one?
This calculator uses a date difference with a zero-day start. For a milestone that counts the start date as day one, use the 100th Day Calculator.