What if I enter the end date before the start date?

The calculator swaps them automatically and shows a note, so you always get a positive difference regardless of which date you typed first.

Why don't total months and (years × 12 + months) always look the same as the days count?

Months have different lengths, so "3 months and 10 days" isn't a fixed number of days — the years/months/days breakdown follows the calendar, while total days is an exact day count between the two dates.

Does this include both the start and end date in the count?

The total days figure is the number of days between the two dates (exclusive of one endpoint), matching how calendar duration is normally expressed — for an inclusive day count, add 1 to the total.

Is my date data sent anywhere?

No. All math runs locally in your browser — nothing is transmitted or stored.

DATE DIFFERENCE CALCULATOR

Find the exact gap between two dates. Nothing leaves your browser.

Start date

End date

Difference

0y 1m 0d

Total months1

Total weeks4

Total days31

How to find the difference between two dates

1
Enter a start date and an end date.
2
If the end date is earlier than the start date, they're automatically swapped.
3
Read the difference as years/months/days, plus total months, weeks, and days.

Questions

What if I enter the end date before the start date?: The calculator swaps them automatically and shows a note, so you always get a positive difference regardless of which date you typed first.
Why don't total months and (years × 12 + months) always look the same as the days count?: Months have different lengths, so "3 months and 10 days" isn't a fixed number of days — the years/months/days breakdown follows the calendar, while total days is an exact day count between the two dates.
Does this include both the start and end date in the count?: The total days figure is the number of days between the two dates (exclusive of one endpoint), matching how calendar duration is normally expressed — for an inclusive day count, add 1 to the total.
Is my date data sent anywhere?: No. All math runs locally in your browser — nothing is transmitted or stored.