Overview
This tool reverses the add-days calculator: enter a date and a number of days to find the earlier date. Useful for reviewing past deadlines or finding when a period began.
Formula
Subtract the number of days from the start date in the Gregorian calendar, accounting for month lengths and leap years.
How it works
Pick the start date
The date you are subtracting from.
Enter the number of days
How many days to go back.
Read the result
The earlier date and weekday appear.
Worked examples
30 days earlier
Subtracting 30 days from March 1, 2026 gives January 30, 2026.
A week earlier
Subtracting 7 days from November 10, 2026 gives November 3, 2026.
Frequently asked questions
Is the start date included?
No. The result is the start date minus the number of days.
What if the subtraction crosses into the previous year?
The calculator rolls back to the previous year and adjusts for month length.
Can I subtract a large number of days?
Yes, up to 100,000 days, with leap years included.
This calculator is for educational and informational purposes only and is not a substitute for professional advice.