Use this calculator to determine the number of hours and minutes between two times or two dates and times. This tool is ideal for various tasks, such as:
For a comprehensive timesheet with daily entries, consider using a dedicated Time Card Calculator.
Enter the start and end times to calculate the duration. Results update automatically. Use the "Now" button to fill in the current time, or "Swap" to reverse the start and end times.
Enter the start and end dates and times to calculate the duration across multiple days. Results update automatically. Useful for tracking long-term projects, travel durations, or multi-day event planning.
This table provides a reference for the number of hours in various time periods, useful for planning and estimating time for projects, budgets, or schedules.
| 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 decade with 2 leap years 87,672 for a decade with 3 leap years 87,660 on average |
| Hours in a century | 876,600 |
An hour is a unit of time equal to 60 minutes, with each minute consisting of 60 seconds. A day has 24 hours. Time is commonly read using either a 12-hour or 24-hour clock, each serving different needs based on clarity and context.
The 12-hour clock uses numbers from 1 to 12, with "AM" (ante meridiem, before noon) and "PM" (post meridiem, after noon) to distinguish between morning and afternoon hours. For example, 12 AM represents midnight, and 12 PM represents noon. This format is widely used in everyday settings, such as scheduling appointments or reading analog clocks. To avoid confusion, terms like "12 midnight" or "12 noon" may be used. This format is common in countries like the United States.
The 24-hour clock uses numbers from 0 to 23, starting at 00:00 (midnight) and ending at 23:59. This format eliminates ambiguity, as each hour is uniquely represented. For example, 13:00 corresponds to 1:00 PM in a 12-hour clock. The 24-hour clock is often referred to as "military time" in some regions and is standard in fields like the military, aviation, and medicine, where time precision is critical. It is also the international standard for time measurement, widely used in countries across Europe, Asia, and beyond.
Use the 12-hour clock for informal settings, such as personal schedules or casual communication. Opt for the 24-hour clock in professional or technical environments where clarity is essential, such as logistics, programming, or international coordination. This calculator supports input in both 12-hour and 24-hour formats for ease of use, with internal conversion to ensure accurate calculations.
This calculator can be used in various scenarios:
By understanding time differences, you can better plan and manage your activities, ensuring efficiency and accuracy in your time-related tasks.