Time Converter

Time conversion translates a value between milliseconds, seconds, minutes, hours, days, weeks, months and years. This tool converts every unit through a common second (s) base so any pair can be computed instantly.

Enter a value, choose the from and to units, and the result updates automatically. Use Swap units to flip the two selections.

Result = value × (from-unit seconds) ÷ (to-unit seconds)

Common conversions: 1 minute = 60s, 1 hour = 3,600s, 1 day = 86,400s, 1 week = 604,800s.

The actual time it takes Earth to orbit the Sun (a tropical year) isn't exactly 365 days — it's about 365.2422 days. Counting every year as 365 days would accumulate roughly 24.22 days of drift per century, pushing the calendar out of sync with the seasons, so the Gregorian calendar applies a 3-step correction: ① a year divisible by 4 is a leap year (adds Feb 29), ② but one also divisible by 100 reverts to a common year, ③ unless it's also divisible by 400, in which case it's a leap year again. Applying these three steps gives the Gregorian calendar an average year length of 365 + 1/4 − 1/100 + 1/400 = 365.2425 days, narrowing the gap with the true tropical year (365.2422 days) to about one day every 3,300 years. That's exactly why 2000 (divisible by 400) was a leap year while 1900 (divisible by 100 but not 400) was not.

Computer systems, meanwhile, don't store dates in human-readable form — they use Unix time: the number of seconds elapsed since 00:00:00 UTC on January 1, 1970 (the epoch, 0). Most server logs, API timestamps and database columns use this format. Adding 86,400 seconds per day, 31,536,000 for a common year (365 days), or 31,622,400 for a leap year (366 days) to a Unix timestamp lets you compute dates directly.