Date calculator: add days to a date or count the days between two dates

You need to set and unit
Can't read this date

Date Calculator

Any math with dates with and keep it simple as possible

Dates
25.12.2026, 2026-12-25, 12/25/2026, 22 Nov 1996, today, next Friday, следующую пятницу, щас. A date that stops at the month is the first day of it: November 1996, ноябрь 1996, 11.1996, 2026
Amounts
10 days, 33y, 1ч30м, -4 weeks 4 days, 3 сек
Ranges
22.11.1996 - 25.11.1996, today - 29.08.2026 — every day in between; a picked run of four days or more is written back this way
Between
a second date instead of an amount gives the gap between the two
Repeats
* 2 days, every week, каждые 3 дня — every day in the first field moves on by that step. A range moves as a block instead: 22.11.1996 - 25.11.1996 with * 4 d is four days on, four days off
Days off
the ( ) button next to the grid puts brackets on a repeat: * week (04.05.2026 - 10.05.2026). Days picked while it is on go inside them and drop out of the repeat, and a turn with nothing left in it is skipped whole
Calendar
click fills the first field, ctrl-click the second, shift-click or a long press picks several days. The month title is a field of its own, and it reads whatever the first field reads — November 1996, ноябрь 1996, 11.1996, next year — the grid opens there instead of on today
Keys
Enter calculates, Tab swaps fields, Esc steps out of them; on desktop just start typing anywhere
Answers
share one as a link, or send a single date to Google Calendar — a repeat travels with it