One gap, shown in whatever unit you need
The raw answer is the difference between two moments. Everything else is the same span converted: divide by the length of a day for total days, by seven for weeks, or break it into years, months and days for a human-readable figure.
The years-months-days breakdown
A calendar breakdown subtracts years, then months, then days, and borrows from the next unit up when a value goes negative, the same way you borrow when subtracting by hand.
- Days short? Borrow the length of the previous month and drop the month count by one.
- Months short? Add twelve months and drop the year count by one.
- Total versus breakdown. The same span is both, say, a large flat number of days and a tidy years-months-days figure; neither is more correct.
The settings that change the answer
- Inclusive end. Whether the final day is counted shifts the total by one. Decide whether you mean a window length or a from-and-to count.
- Business days only. Dropping weekends leaves roughly 260 weekdays in a full year, before any holidays.
- Leap days. A span that crosses 29 February is one day longer than the same span in a non-leap stretch.
- Weeks are not week-boundaries. Seven days is one week, but going from a weekday to the same weekday is eight days if you count both ends.
Common questions
How is the time between two dates worked out?
The tool takes the gap between the two timestamps and expresses it in whatever unit you want: total days, hours and minutes, weeks, or a years-months-days breakdown. They are all the same span shown differently.
Does the count include the end date?
That depends on the inclusive setting. Counting from one day to the same day is zero days if the end is excluded, or one day if it is included. For a same-length window like a two-week trial you usually want it excluded.
How many days does a year hold?
A common year has 365 days and a leap year has 366. A leap year is any year divisible by 4, except century years, which must be divisible by 400. So 2000 was a leap year and 2100 will not be.
