How Many Days Since Calculator
Count how many days have passed since a date in the past.
Results update as you type.
About this calculator
This calculator counts the days that have elapsed since a past date — a birthday, an anniversary, a start date or any milestone — and also breaks the gap down into years, months and days. Use it to track how long ago something happened or how long you have kept a streak going.
Frequently asked questions
How is "days since" different from a date difference?
It always measures from the past date up to today, so you never have to enter the second date. The full date-difference tool lets you pick both ends of the range yourself.
Why show years, months and days as well?
A raw day count like 400 days is hard to picture, so the calculator also gives the same gap as "1 year, 1 month, 5 days", which is easier to read for long spans.
Results are estimates for general guidance only, not financial, medical or tax advice.