Everyday Life
Date calculator
Count the time between two dates, or move a date forward or back by days, weeks, months, or years. The calculator shows the calendar-day gap, the equivalent weeks and days, and the weekday. Month and year changes handle short months sensibly: adding one month to January 31 lands on the last day of February.
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Date Calculator
Count days between dates or add and subtract days, weeks, months, and years.
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Daily plannerKeep due dates, appointments, and date notes together.Paid link · Check current price ↗As an Amazon Associate I earn from qualifying purchases.The math, plainly
How it works
- 01
Days between dates are elapsed calendar days: the starting date is day zero, rather than counting both endpoints as full days.
- 02
Adding or subtracting days and weeks uses calendar days. For months and years, the calculator keeps the day number when it exists; if the destination month is shorter, it uses that month's last day.
- 03
The weekday is calculated from the actual calendar date, including leap years. This tool does not remove weekends or public holidays.
Try a real scenario
Add one month to January 31
InputsStarting date January 31, 2026; add 1 month
ResultFebruary 28, 2026, a Saturday.
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As an Amazon Associate I earn from qualifying purchases.