DATE & DURATION

Subtract Time Calculator

Enter a date and time, choose a duration to subtract, and get the resulting date and time.

Subtract a duration from a date and time

Enter a date and time, a time zone, an amount and a unit, and the tool returns the date and time that far before it. This answers questions like “what date was 90 days before this deadline” or “what time did this 6-hour job start if it finished at 14:00.”

Exact time vs calendar days

Seconds, minutes and hours subtract an exact amount of elapsed time. Days and weeks go back by calendar days in the time zone you choose and keep the same clock time, even across a daylight saving change. If that lands in a gap created by clocks moving forward, the tool moves the result forward by the size of the gap and explains why.

Want the background? Read our comprehensive guide: Time Zones and DST for Developers.

How to use this tool

Enter the date and time to subtract from, or select Use current time.
Choose the time zone.
Enter the amount to subtract and choose the unit.
Select Subtract time to see the resulting date and time.

Examples

Subtracting a calendar unit (days) and an exact-time unit (minutes).

Subtract 90 days

2026-09-21 12:00 UTC − 90 days

Result: 2026-06-23T12:00:00.000Z

Subtract 45 minutes

2026-09-21 12:00 UTC − 45 minutes

Result: 2026-09-21T11:15:00.000Z

Subtract 2 weeks

2026-09-21 12:00 UTC − 2 weeks

Result: 2026-09-07T12:00:00.000Z

Frequently Asked Questions

How do I find the date a number of days ago?

Enter today's date, set the unit to Days, enter the number of days, and select Subtract time.

Does subtracting days keep the same time of day?

Yes, days and weeks keep the clock time and move the calendar date backward, including across a daylight saving change.

Can the result be a negative number of days?

No. The result is always a specific date and time; if you need the size of a gap between two dates instead, use the Date Difference Calculator.

How do I add time instead?

Use the Add Time Calculator, which works the same way but moves forward from the starting date and time.