Everything you need to know about time unit conversion
One day contains 86,400,000 milliseconds. This is calculated as: 24 hours × 60 minutes × 60 seconds × 1,000 milliseconds = 86,400,000 ms. This conversion is commonly used in programming for timestamp calculations, especially when working with Unix timestamps or JavaScript Date objects.
Multiply the number of hours by 3,600 (since 1 hour = 60 minutes × 60 seconds). For example, 5 hours = 5 × 3,600 = 18,000 seconds. Our converter does this instantly for any value, including decimal hours like 2.5 hours (which equals 9,000 seconds).
Remember the base conversions: 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, and 7 days in a week. For milliseconds, remember that "milli" means thousand, so 1,000 milliseconds = 1 second. A helpful mnemonic: "Sixty-Sixty-Twenty-Four-Seven" represents the conversion factors from seconds up to weeks.
The 24-hour day system dates back to ancient Egypt, where they divided daylight into 12 hours and nighttime into 12 hours. This base-12 system was practical for ancient timekeeping methods and has persisted to modern times. The Egyptians likely chose 12 because it's easily divisible by 2, 3, 4, and 6, making it convenient for mathematical calculations.
This tool maintains high precision in calculations, displaying up to 6 decimal places for accuracy. This level of precision is sufficient for virtually all practical applications, from scientific calculations to software development. The calculations use JavaScript's native number type, which provides IEEE 754 double-precision floating-point accuracy.
This tool converts between time units (like hours to minutes), not between timezones. For timezone conversions, you would need a different tool that accounts for geographic time differences, UTC offsets, and daylight saving time adjustments. However, you can use this tool to calculate time differences between zones if you know the hour offset.
One week contains 604,800 seconds. This is calculated as: 7 days × 24 hours × 60 minutes × 60 seconds = 604,800 seconds. This is useful for calculating weekly timeframes in programming, subscription services, or project planning.
Business days (or work days) typically refer to Monday through Friday, excluding weekends and holidays, which means there are usually 5 business days per week. Calendar days include all days of the week, totaling 7 days per week. When converting weeks to days for project planning, it's important to specify whether you're counting business days (5 per week) or calendar days (7 per week).
To convert decimal hours (like 2.5 hours) to hours and minutes: the whole number is the hours (2), and multiply the decimal part by 60 to get minutes (0.5 × 60 = 30 minutes). So 2.5 hours = 2 hours and 30 minutes. Our tool shows both decimal values and can help you understand these relationships by showing all units simultaneously.
The base-60 (sexagesimal) system for time comes from ancient Babylon. They chose 60 because it has many divisors (1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60), making it easy to divide into equal parts. This is why we have 60 seconds in a minute and 60 minutes in an hour, rather than using the decimal (base-10) system we use for most other measurements.
Our time converter tool makes it easy to perform accurate conversions between different time units. Here are some tips for getting the most out of the tool:
This time converter is particularly useful for:
When working with very large or very small numbers, it's important to understand how precision works. Our tool displays up to 6 decimal places for most values, which provides more than enough accuracy for practical applications. For extremely small values (less than 0.000001), the tool uses scientific notation to maintain readability.
If you're looking for more information about time conversion and measurement, consider exploring these related topics: