Hours Calculator
Use the calculator below to find the total number of hours and minutes between two times. For a full time card, please use the Time Card Calculator.
Hours Between Two Dates
Understanding Time and Hour Formats
An hour is defined as a time unit made up of 60 minutes, where each minute equals 60 seconds. A full day contains 24 hours. Most people measure or read time using either a 12-hour or a 24-hour clock.
12-hour clock:
A 12-hour clock divides the day into two parts using the numbers 1–12. “AM” represents hours before noon, and “PM” represents hours after noon. 12 AM is midnight, and 12 PM is noon. To make it unambiguous, people sometimes say “12 midnight” or “12 noon.”
24-hour clock:
The 24-hour format counts the day from 00:00 (midnight) to 23:59. It avoids AM/PM confusion and is internationally accepted. Hours 00–11 cover morning, and 12–23 cover afternoon and evening. This format is used by the military and global transport systems for accuracy.
Hours in different time periods
| Description | Hours |
|---|---|
| Hours in a day | 24 |
| Hours in a week | 168 |
| Hours in a month |
672 for a 28-day month 696 for a 29-day month 720 for a 30-day month 744 for a 31-day month 730.5 on average |
| Hours in a year |
8,760 for a 365-day year 8,784 for a 366-day year 8,766 on average |
| Hours in a decade |
87,648 for a 2-leap-year decade 87,672 for a 3-leap-year decade 87,660 on average |
| Hours in a century | 876,600 |