The time calculator has three modes: Duration, Date and Expression. Choose the mode that matches your task, enter your values and read the result in days, hours, minutes and seconds.
Add two durations
- Open Time Calculator and select Duration.
- Enter the first duration in the day, hour, minute and second fields.
- Choose Add.
- Enter the second duration.
- Read the result and use Copy if you want to save it elsewhere.
For example, 2 hours 45 minutes plus 1 hour 30 minutes equals 4 hours 15 minutes. The calculator carries 60 minutes into 1 hour. Empty fields count as zero.
Subtract a duration
In Duration mode, choose Subtract to take the second duration away from the first.
For example, 8 hours 30 minutes minus 45 minutes equals 7 hours 45 minutes. Subtracting 2 hours from 1 hour produces −1 hour.
Add or subtract time from a date
- Select Date.
- Choose your starting date and clock time, or select Use current time.
- Choose the 12-hour or 24-hour display. In 12-hour format, check AM or PM.
- Select Add or Subtract.
- Enter the days, hours, minutes and seconds to move.
- Read the resulting date and time.
For example, 15 October 2026 at 10:00 AM plus 2 hours 30 minutes is 15 October 2026 at 12:30 PM, provided no local clock transition occurs during that interval.
The date mode uses your device’s local time settings. It does not offer a destination time-zone selector in the retrieved interface.
Calendar days and elapsed hours
Adding 1 calendar day keeps the local clock time on the next calendar date. Adding 24 hours moves by 24 elapsed hours. These can give different local clock times across a daylight saving transition.
For an ordinary duration or expression, 1 day represents 24 hours. For a date shift, a day is a calendar step. Choose the unit that fits your task.
Write a time expression
Select Expression and put a unit after each number:
| Unit | Meaning | Example |
|---|---|---|
| d | Days | 1d |
| h | Hours | 2h |
| m | Minutes | 30m |
| s | Seconds | 45s |
Use plus and minus between groups. A group such as 1h 30m combines those units.
| Expression | Result |
|---|---|
| 2h + 45m | 2 hours 45 minutes |
| 8h 30m – 45m | 7 hours 45 minutes |
| 1d 3h – 90m | 1 day 1 hour 30 minutes |
| 1.5h + 90s | 1 hour 31 minutes 30 seconds |
| 2h – 90m | 30 minutes |
Use the documented + and – operators. Multiplication, division and parentheses are not part of the documented expression format.
Decimal hours are different from hours and minutes
The expression 1.5h means 1.5 × 60 = 90 minutes. It does not mean 1 hour 50 minutes. To convert a fraction of an hour to minutes, multiply the fraction by 60.
For example, 1 hour 45 minutes = 1.75 hours because 45 ÷ 60 = 0.75.
Check your result
Confirm the mode, units, addition or subtraction, and AM/PM setting. For dates, also confirm your device time zone. For pay, legal deadlines or other consequential decisions, independently verify the result and any applicable rules.
See the FAQ or report a problem.