Date Calculator: Days Between Dates, Add or Subtract
Subtract the earlier date from the later one to get the days between them. From 1 January to 25 December 2026 is 358 days, or 359 if you count both the first and last day.
Pick an end date to count the days.
Counting the days between two dates
The calculator counts whole calendar days, so daylight saving changes never add or remove a day. By default the start date is counted but the end date is not, the way most people count nights or days remaining. Tick “Include the end date” to count both days, which is common for hotel stays, project durations or “day 1 to day 30” style plans.
The result is shown as total days, as weeks and days, and as years, months and days. Working days count Monday to Friday only. Public holidays are not removed because they vary by country and region.
Adding and subtracting time
Switch to Add or subtract to find a date in the future or the past: 90 days from a contract date, 6 weeks after a procedure, 18 months from now. Years and months are added on the calendar, and weeks and days are added afterwards. If the day does not exist in the new month, the last day of that month is used, so 31 January plus one month is 28 February.
The weekday of the result is shown too, which helps when planning deadlines, appointments and events.
Common uses
People use date calculators for notice periods and deadlines, warranty and return windows, pregnancy and treatment schedules, visa and travel limits, loan and invoice terms, countdowns to events and finding how long ago something happened. Because each step is displayed, you can also use the result to check a manual count or explain it to someone else.
Frequently asked questions
- How many days are there between two dates?
- Subtract the earlier date from the later. From 1 January to 25 December 2026 is 358 days.
- Does the calculation include the end date?
- Not by default. Tick “Include the end date” to add one day and count both the start and end dates.
- How are working days counted?
- Every Monday to Friday between the dates is counted. Weekends are skipped, but public holidays are not because they differ by location.
- How do I find the date 90 days from today?
- Choose Add or subtract, leave the start date as today, enter 90 in the days box and read the result and its weekday.