Work with dates: count the days between two dates, add or subtract a duration, get someone's exact age, and look up the ISO week number, day of year and other facts about any date.
Runs entirely in your browser. Nothing you put in here gets uploaded.
Leave the start empty to count from today.
Pick an end date to compare against the start.
This tool answers the everyday date questions in one place. Count the days between two dates, move a date forward or back by a duration, work out an exact age, and look up facts like the ISO week number for any date.
Every date can be typed straight into its field or picked from a calendar, and a start date left empty counts from today.
The gap between two dates is shown in two ways. The calendar breakdown counts whole years and months first and then the days that remain, which is how people state ages and anniversaries. The totals count plain days, full weeks, working days from Monday to Friday, hours and minutes. By default the end date itself is not counted, so 1 January to 2 January is 1 day. Turn on the end date toggle to count it as well, which is common for bookings and billing.
Adding months keeps the day of the month where it can. When the target month is shorter, the date is clamped to that month's last day, so 31 January plus one month lands on 28 February, or on 29 February in a leap year. The tool points it out whenever this happens. The same rule decides that a 29 February birthday is celebrated on 28 February in non-leap years.
Week numbers follow ISO 8601, where week 1 is the week that contains the year's first Thursday and weeks start on Monday. That is why the first days of January can still belong to the last week of the previous year, and 29 to 31 December can already sit in week 1 of the next one. To turn a date into a Unix timestamp instead, use the Unix Timestamp Converter.
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