How to use the add or subtract days
Enter a starting date and a number of days. Use a negative number to subtract days.
How the calculation works
Calendar-day arithmetic includes weekends and leap days. This is not a business-day calculator: use the weekday tool if you need working days only.
Check your inputs carefully: an incorrect date can change a result. Dates and times are entered using your device settings, and no account is needed. For formal, legal, medical or financial purposes, verify the applicable local rules and official records.
Frequently asked questions
Can I enter negative numbers?
Yes. Enter -14 to calculate the date exactly two weeks earlier.
Which time zone is used?
Dates use your device’s local calendar day. Date-only calculations avoid daylight-saving day-length errors.
Are the dates I enter uploaded?
No. AgeGlide calculates your results in your browser. Entered dates are not sent to our server for processing.