Time unit converter
Convert time units between seconds, minutes, hours, days, weeks, months, and years.
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Common time units
Second (s)
Definition: The second (symbol: s) is the SI base unit of time. Since 1967, it has been defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom.
History/origin: Historically, the second was defined as 1/86,400 of a mean solar day (24 hours × 60 minutes × 60 seconds). With advances in atomic physics, the definition was moved to an atomic standard in 1967 for much greater precision and stability.
Current use: The second is universal across all domains: science, engineering, computing, and everyday life. It is the foundation for all other time units and is used in GPS systems, telecommunications, financial transactions, and scientific measurements.
Minute (min)
Definition: A minute (symbol: min) is a unit of time equal to 60 seconds. There are 60 minutes in an hour, making one minute equal to 1/1,440 of a day.
History/origin: The division of the hour into 60 minutes comes from the Babylonian base-60 numeral system, used over 4,000 years ago. The word "minute" derives from the Latin "pars minuta prima", meaning first small part, referring to the first division of the hour.
Current use: Minutes are used universally for scheduling, cooking times, sports, and measuring short durations. Clocks, calendars, and timers around the world display time in hours and minutes.
Hour (h)
Definition: An hour (symbol: h) is a unit of time equal to 60 minutes, or 3,600 seconds. There are 24 hours in a day.
History/origin: The division of the day into 24 hours originates with the ancient Egyptians, who divided daylight and night each into 12 parts. The Babylonians and Greeks further refined the system into the 24-hour day used universally today.
Current use: Hours are the primary unit for scheduling work, transportation, and events. Hourly wages, flight durations, and business hours are all expressed in hours. The 24-hour clock is standard in most of the world, while the 12-hour AM/PM format is common in the US and UK.
Day
Definition: A day is a unit of time equal to 24 hours, or 86,400 seconds. It corresponds to one full rotation of the Earth on its axis relative to the Sun (a solar day).
History/origin: The concept of a day is as old as human civilization, defined by the natural cycle of daylight and darkness. Ancient cultures built calendars around the solar day, and it remains the fundamental unit of human scheduling.
Current use: Days are used in calendars, project timelines, shipping estimates, medication schedules, and virtually every area of daily planning. Most deadline and scheduling systems are day-based.
Time conversion table
| From | To | Result |
|---|---|---|
| 1 Minute (min) | Seconds (s) | 60 s |
| 1 Hour (h) | Minutes (min) | 60 min |
| 1 Hour (h) | Seconds (s) | 3,600 s |
| 1 Day | Hours (h) | 24 h |
| 1 Day | Seconds (s) | 86,400 s |
| 1 Week | Days | 7 days |
| 1 Week | Hours (h) | 168 h |
| 1 Month (avg) | Days | 30.4375 days |
| 1 Year (avg) | Days | 365.25 days |
| 1 Year (avg) | Hours (h) | 8,766 h |
| 1 Year (avg) | Seconds (s) | 31,557,600 s |
How to convert time units
Time conversions use fixed multiplication factors based on exact definitions (60 seconds per minute, 60 minutes per hour, 24 hours per day, and so on).
Hours to seconds
seconds = hours × 3600
Example: 2.5 h = 2.5 × 3600 = 9,000 s
Days to hours
hours = days × 24
Example: 7 days = 7 × 24 = 168 h
Years to days
days = years × 365.25
Example: 3 years = 3 × 365.25 = 1,095.75 days
Frequently asked questions
How many seconds are in a day?
There are 86,400 seconds in one day (60 seconds × 60 minutes × 24 hours). One week is 604,800 seconds. This value is commonly needed in software development for setting cache TTLs, token expiry times, and rate limits expressed in seconds.
How many seconds are in a year?
One standard year (365 days) contains 31,536,000 seconds. Using the average year of 365.25 days (to account for leap years), the value is 31,557,600 seconds. The 365.25-day average is more accurate for long-range calculations involving multiple years.
How many minutes are in a day?
There are 1,440 minutes in one day (60 minutes × 24 hours). One week contains 10,080 minutes. One year contains approximately 525,960 minutes (365.25 × 1,440).
How do I convert hours to minutes?
Multiply the number of hours by 60. For example, 2.5 hours = 2.5 × 60 = 150 minutes. To convert minutes to hours, divide by 60. For example, 90 minutes = 90 ÷ 60 = 1.5 hours (1 hour 30 minutes).
How many hours are in a week?
There are 168 hours in one week (24 hours × 7 days). A standard working week of 40 hours represents 40/168 = 23.8% of the total hours in a week. A full-time employee works approximately 2,080 hours per year (40 hours × 52 weeks).
How do I convert days to weeks and months?
To convert days to weeks, divide by 7. To convert days to months, divide by 30.4375 (the average month length accounting for all months and leap years). Note that month conversions are approximate — calendar months vary from 28 to 31 days, so a precise answer depends on which specific months are involved.
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