Date Difference Calculator

Enter a start date and an end date and the tool returns the gap as years, months and days, plus totals in months, weeks, days and hours. It counts the days you move forward to get from one date to the other, so the start date is included and the end date is not.

For 19 October 2026 to 31 March 2027 the result is 5 months, 12 days, which is 163 days, 23 weeks or 3,912 hours. Two identical dates give zero.

There is no switch for including the end date. When you need it counted, add one day to the total yourself, as the next section explains.

Whether you add a day depends on what you are measuring:

• Nights, elapsed time, ages and deadlines "in X days": use the number as shown. A stay from the 10th to the 13th is 3 nights.
• Days on which something happens: add one. An event that runs from the 10th to the 13th covers 4 days.

A full calendar year shows the difference clearly. From 1 January 2026 to 31 December 2026 the tool gives 364 days, because 31 December itself isn't counted. If you mean "every day of 2026", the answer is 365.

When you write a date range in a contract or a leave request, say which convention you mean, for example "from 10 March to 13 March, both days inclusive".

The months figure follows the calendar, so a month is however long that month happens to be. These are the tool's results:

The last row catches people out. The end of January to the end of February feels like a month, but because the 28th comes before the 31st, the tool reports 28 days and no full month.

When money depends on the answer, use the line that matches how the price is set. A daily rate needs the total days; a monthly rate needs the months figure, with the leftover days handled however your agreement says.

The week total is the day total divided by 7 and rounded down. A 67-day span shows as 9 weeks; the 4 days left over are not shown, so multiply back (9 × 7 = 63) if you need them.

Hours are the day total multiplied by 24. The tool works with dates, not times, so it can't tell you the hours between 9:00 on one day and 17:30 on another. For clock times, use the Hours Calculator on this site.