Hours Calculator
Use the calculators below to find the number of hours and minutes between two times.
Hours Between Two Dates
Understanding Hours and Time Measurement
An hour is most commonly defined as 60 minutes, where each minute equals 60 seconds. There are 24 hours in a day. People typically read time using either a 12-hour clock or a 24-hour clock.
12-Hour Clock
Uses numbers 1–12.
AM (ante meridiem) means “before midday.”
PM (post meridiem) means “after midday.”
12 AM = midnight, 12 PM = noon.
To avoid confusion, use “12 midnight” or “12 noon.”
24-Hour Clock
Uses numbers 00–23.
00:00 = midnight, 12:00 = noon.
Eliminates AM/PM confusion.
Often called military time because it is widely used by militaries and organizations needing precise, unambiguous time measurement.
Hours in Different Time Periods
| Time Period | Hours |
|---|---|
| Day | 24 |
| Week | 168 |
| Month (28 days) | 672 |
| Month (29 days) | 696 |
| Month (30 days) | 720 |
| Month (31 days) | 744 |
| Month (average) | 730.5 |
| Year (365 days) | 8,760 |
| Year (366 days) | 8,784 |
| Year (average) | 8,766 |
| Decade (2 leap years) | 87,648 |
| Decade (3 leap years) | 87,672 |
| Decade (average) | 87,660 |
| Century | 876,600 |