Date Calculator
Count the days between two dates, or add and subtract days, weeks, months and years and see the resulting weekday.
How to use
- Choose a mode at the top — ‘Date difference’ or ‘Add or subtract’.
- Date difference: pick a start and an end date to see total days, weeks, months and years.
- Switch on ‘Include the start day’ to count the first date as day one.
- Add or subtract: set a base date, an amount and a unit to get the resulting date and weekday.
FAQ
Is the start date counted in the difference?
Not by default. Switch on ‘Include the start day’ to count it as day one.
What happens if I add one month to 31 January?
A date that does not exist in the target month is clamped to that month's last day, so 31 January + 1 month is 28 February (29 in a leap year).
How are months and years counted?
On the real calendar. Months means whole months, ignoring leftover days.
Are weekends and holidays counted?
Yes — only calendar dates are counted, so weekends and holidays are included.
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