Hours between two dates
Calculate the exact number of hours - and minutes, and seconds - between any two points in time.
How the hours are calculated
The tool subtracts the start time from the end time and divides by 3,600,000, the number of milliseconds in an hour. You get the whole hours, the leftover minutes and seconds, and the same span in total minutes and days. If the end is before the start, it shows the absolute difference and tells you.
For example, from Friday at 9:00 AM to Monday at 5:00 PM is 80 hours: three full days of 24 hours, plus 8 more.
Daylight saving time and time zones
Both times are read in your device’s time zone, and the result is the real time that passes. That matters on the nights clocks change: a span that crosses the start of daylight saving time is one hour shorter than the calendar suggests, and one that crosses the end is one hour longer. If your two times are in different time zones, convert one of them first; the time zone meeting planner helps.
Common spans in hours
| Span | Hours |
|---|---|
| 1 day | 24 |
| 1 week | 168 |
| 30 days | 720 |
| A 365-day year | 8,760 |
| A 366-day leap year | 8,784 |
Hours for timesheets
Timesheets and invoices often need decimal hours. Divide the minutes by 60: 7 hours 45 minutes is 7.75 hours, and 20 minutes is about 0.33 hours. This tool counts every hour, including nights and weekends; for working time only, use the working hours calculator or the business days calculator.
Count down the hours
For a deadline, a flight or an exam, Left can show an Ahead countdown in hours instead of days, on your Home Screen or Lock Screen.
Questions
How many hours are in a week?
A week has 168 hours (7 × 24). A 30-day month has 720 hours and a 365-day year has 8,760.
Does it account for daylight saving time?
Yes. It measures the real time that passes in your device’s time zone, so a span that crosses a clock change is one hour shorter or longer than the calendar suggests.
How do I convert minutes to decimal hours?
Divide the minutes by 60. For example, 45 minutes is 0.75 hours, so 7 hours 45 minutes is 7.75 hours.
Can I calculate hours between two time zones?
Convert both times to the same time zone first, then enter them. The tool reads both times in your device’s time zone.
Start noticing what matters.
Download Left on your iPhone to see the time you have left, dates you are looking forward to, build the habits you want to keep, and become a better version of yourself.
Scan or search "Left" on the App Store.