Date Calculator (Add or Subtract Days)
Add or subtract days, weeks, months and years to a date and see the result and weekday.
Result
If the day does not exist in the target month (e.g. 31 February), the last day of that month is used.
Find a deadline easily
Work out an invoice due date 30 days out, the end of a 90-day trial, when a 6-month contract ends or a medication's expiry with the date calculator.
Flexible calculation
- Add or subtract days, weeks, months and years
- Combine several units (e.g. 1 year 2 months 10 days)
- See which weekday the result falls on
Calendar-aware months
Months and years are added according to the calendar. Adding one month to 31 January gives the last day of February, so you never get an invalid date.
How to use Date Calculator (Add or Subtract Days)
- Choose the start date.
- Enter the amounts to add or subtract.
- Choose add or subtract.
- See the resulting date and weekday.
Why use this tool?
Calculate legal deadlines, payment terms and delivery dates without mistakes.
FAQ
What is 31 January + 1 month?
February has no 31st, so the result is set to the last day of February (28 or 29).
I want to add business days.
Use the Business Days Calculator to skip weekends and holidays.
Can I find a date in the past?
Yes, subtract to find, for example, the date 100 days ago.
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