Subtract Days from a Date
Pick a date and how much time to go back.
Resulting date
—
ISO format
—
Days from start
—
How it works
- Pick a start date.
- Enter how many days, weeks, months or years to go back.
- See the earlier date and its day of the week.
Frequently asked questions
How do I find the date 90 days ago?
Leave today's date as the start, enter 90 and choose days. The result updates instantly.
How are months subtracted from the end of a month?
The result is clamped to a valid date, so 31 March − 1 month = 28 or 29 February.
Why would I subtract days from a date?
To find a return-window start, a notice-period deadline, a conception or due-date estimate, or when a 30-day period began.
Can I switch to adding days?
Yes. Change the operation to Add, or use the Add Days to Date tool.
Count back from any date
Work out when a 14-day return window started, what date was 90 days ago, or when to send reminders before a deadline.
Weeks, months and years too
Go back by weeks for schedules, months for billing periods or years for anniversaries — the result shows the full date with its weekday.