Subtract Days Calculator
Find the calendar date a stated number of days before your starting date.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Calendar date | Gregorian calendar date in YYYY-MM-DD format; years 0001 through 9999. |
| Days | integer 0..3652058 |
Understanding your result
Calendar results use the stated counting and anniversary convention. Complete months and years differ from fixed day counts.
Common mistakes
- Counting both end dates when the method excludes a boundary, or assuming all months have equal length.
Check your calculation
- Test a short known interval and a leap-day boundary; for working days, verify your holiday list.
Calculation checks, sources and review limits
What date was a given number of days before this date?
Find the calendar date a stated number of days before your starting date.
Common uses
- Find the calendar date a stated number of days before your starting date.
How it works
result=fromOrdinal(ordinal(date)-days) Calendar arithmetic uses the proleptic Gregorian calendar. Explicit calendar dates are independent of local daylight-saving changes. Month/year additions clamp to the last valid day of the destination month. Timestamp arithmetic requires a stated UTC offset and excludes leap seconds.
Worked example
Enter Calendar date: 2024-03-01; Days: 2. The result is Date: 2024-02-28.
FAQ
What date was a given number of days before this date?
result=fromOrdinal(ordinal(date)-days) Calendar arithmetic uses the proleptic Gregorian calendar. Explicit calendar dates are independent of local daylight-saving changes. Month/year additions clamp to the last valid day of the destination month. Timestamp arithmetic requires a stated UTC offset and excludes leap seconds.
What assumptions and limits apply?
Inputs and results must stay within the stated supported ranges.