Date Calculator

Find how long two dates are apart, or count forward / backward from a date.

Days between two dates

Start date

End date

Days apart excludes the start day; weekday / weekend counts include both endpoints.

Add or subtract from a date

Base date

After (add) Before (subtract)

Years Months Weeks Days

When adding months, a day beyond the month’s length is clamped to its last day (e.g. Jan 31 + 1 month = Feb 28).

About date calculation

The date calculator solves two common problems: how far apart two dates are (e.g. days until a deadline, or years and months between two anniversaries), and counting forward or backward from a date (e.g. a 90-day due date, or 42 days before maternity leave).

All calculations use the Gregorian calendar and run in your browser; the dates you enter are never uploaded or stored on a server.