Date Difference Calculator
Count the days between two dates or date-times: years, months and days breakdown plus total weeks, hours, minutes and seconds, inclusive option.
Choose an end date.
What is Date Difference Calculator?
Calculates the time between two dates, optionally with times of day. The result is shown as years, months and days and also as total days, weeks, months, hours, minutes and seconds.
How to use Date Difference Calculator
- Enter the Start date and End date.
- Tick Include time of day to enter start and end times as well.
- Tick Include end date (+1 day) if both the first and the last day should be counted, e.g. for the length of a trip.
- Read the breakdown and totals; if the end is before the start, the result is shown as negative.
Example
2026-01-01 to 2026-03-10
2 months, 9 days – 68 days – 9 weeks, 5 days
With Include end date: 2 months, 10 days (69 days).
When to use Date Difference Calculator
Use it for project durations, notice periods, countdowns to events or the length of a stay. For working days only, use the business days calculator; for someone's age, use the age calculator.
How Date Difference Calculator works
Dates are converted to day numbers in UTC, so the total number of days is exact and unaffected by time zones or DST. The years/months/days breakdown counts whole calendar months first and then the remaining days (31 January to 1 March is 1 month and 1 day in a common year). With times, the minutes are added and, if the end time is earlier in the day than the start time, one day is borrowed. Times are plain wall-clock times.
Common Use Cases
- Counting days until a deadline or holiday
- Calculating the length of a contract or rental period
- Measuring how long ago something happened
- Computing hours between two shifts or events
FAQs
Is the end date included?
Not by default: the result equals end minus start, like subtracting dates in a spreadsheet. Tick Include end date to add one day.
Does daylight saving time change the number of hours?
No. Times are treated as wall-clock readings, so a day always counts as 24 hours. Use the time zone converter if you need exact instants in a specific zone.
How are months counted when they have different lengths?
Whole calendar months are counted from the start date; when the target month is shorter, the last day of that month is used before counting the remaining days.