How the days between two dates are counted
The number of days is the end date minus the start date, so the start date itself isnât counted. From October 1 to October 10 is 9 days.
If you want the total number of days, for example for a trip, a hospital stay or time off, both the first and last day count, so add 1: thatâs 10 days. Tick âInclude both the start and end dateâ to do this automatically.
How months and days are counted
The calculator first counts whole calendar months from the start date, then the days left over. From March 15 to October 19 is 7 months to October 15, plus 4 days: 7 months, 4 days.
When the next month has no matching day, the last day of that month is used. So January 31 plus 1 month is February 28, or February 29 in a leap year. Leap years are handled automatically.
Common questions and how to fill them in
| You want to know | Fill in |
|---|---|
| How many days until a date | Start date: today. End date: that date. |
| How many days since a date | Start date: that date. End date: today. |
| What date is 30 days from now | Add or subtract days: start date today, days 30. |
| What date was 90 days ago | Add or subtract days: days -90. |
| Pregnancy due date | Add or subtract days: start date is the first day of the last period, days 280. |
| Total days of a trip or leave | Days between, with âInclude both the start and end dateâ ticked. |
Frequently asked questions
Does âdays untilâ include today?
Usually not, and the calculator doesnât by default. If today is October 19, October 20 is 1 day away.
Which date is âwithin 30 daysâ?
It depends on whether the start date counts. Counting from the day after, 30 days from October 19 ends on November 18. Counting October 19 as day 1, it ends on November 17. Use the âCount the start date as day 1â option to switch. Contracts, bills and laws can define deadlines differently, so check the exact wording.
Are weekends and holidays excluded?
No. The calculator counts calendar days, including weekends and public holidays. For working days, subtract the weekends and the holidays where you live.
Do leap years change the result?
Yes, and the calculator handles them. February has 29 days in a leap year, so a period that crosses February in a leap year is one day longer. The next leap year is 2028.