Date calculator
A date calculator adds or subtracts years, months, weeks and days from a start date. Months are calendar months, not 30-day blocks. Weeks count as seven days. Negative numbers subtract. Workdays skip weekends and observed US federal holidays. The default on this page is today plus 30 days.
Add days, weeks, months, years, or workdays
Date calculator FAQ
How are months added?
Calendar months, not 30-day blocks. 31 January plus one month is 3 March in a common year, because February overflows. Rows run in order, so +1 month then −1 day is a two-step offset.
Can I subtract, or add more than one offset?
Yes. Set a row to minus, or add another offset. Negative years, months, weeks, or days also subtract. Save, CSV, and print need scripting; today plus 30 days stays in the HTML.
Are weeks supported?
Weeks are seven days. They combine with the days field on that row before the offset is applied.
What does add workdays do?
It matches Excel WORKDAY: it moves a number of Monday–Friday dates and skips observed US federal holidays. State holidays are not skipped. Ten workdays from today is in the sidebar as a second default.