Time / Duration Converter
Convert between seconds, minutes, hours, days, weeks, months, years and every other unit of time, from the Planck time to the age of the universe, including astronomical, historical and cultural units.
1 second = 0.000277777778 hours
Most used time units
- Day d 1 d = 86,400 s
- Hour h 1 h = 3,600 s
- Minute min 1 min = 60 s
- Second s Base unit
- Year yr 1 yr = 31,556,952 s
- Month mo 1 mo = 2,629,746 s
- Week wk 1 wk = 604,800 s
- Millisecond ms 1 ms = 0.001 s
- Century c 1 c = 3,155,695,200 s
- Decade dec 1 dec = 315,569,520 s
- Microsecond µs 1 µs = 0.000001 s
- Millennium ka 1 ka = 31,556,952,000 s
Popular time conversions
- Hours to minutes 1 h = 60 min
- Minutes to hours 1 min = 0.01666667 h
- Minutes to seconds 1 min = 60 s
- Seconds to minutes 1 s = 0.01666667 min
- Days to hours 1 d = 24 h
- Hours to days 1 h = 0.04166667 d
- Weeks to days 1 wk = 7 d
- Days to weeks 1 d = 0.1428571 wk
- Years to days 1 yr = 365.2425 d
- Days to years 1 d = 0.002737907 yr
- Months to weeks 1 mo = 4.348125 wk
- Weeks to months 1 wk = 0.2299842 mo
- Milliseconds to seconds 1 ms = 0.001 s
- Seconds to milliseconds 1 s = 1,000 ms
- Hours to seconds 1 h = 3,600 s
- Years to months 1 yr = 12 mo
- Months to years 1 mo = 0.08333333 yr
- Days to months 1 d = 0.03285488 mo
- Years to weeks 1 yr = 52.1775 wk
- Decades to years 1 dec = 10 yr
What is time?
Time measures the duration of events and the intervals between them. The SI unit of time is the second, defined since 1967 by counting 9,192,631,770 oscillations of the radiation from a cesium-133 atom, which is how atomic clocks keep time to within a second in hundreds of millions of years.
Everyday time units are not decimal. Sixty seconds make a minute and sixty minutes an hour, a system inherited from Babylonian base-60 arithmetic; 24 hours make a day, from ancient Egyptian timekeeping. Days, months and years come from the motions of the Earth and Moon, which do not fit neatly together: a year is about 365.2422 days and a lunar month about 29.53 days.
Because months and years vary in length, this converter uses their average Gregorian values: a year of 365.2425 days and a month of one twelfth of that (30.436875 days). Pages for the common year (365 days), leap year, Julian year and astronomical years give their exact lengths.
Common time equivalents
- 1 minute = 60 seconds
- 1 hour = 60 minutes = 3,600 seconds
- 1 day = 24 hours = 1,440 minutes = 86,400 seconds
- 1 week = 7 days = 168 hours
- 1 year (Gregorian average) = 365.2425 days ≈ 52.1775 weeks ≈ 8,765.82 hours
- 1 month (average) ≈ 30.44 days ≈ 4.35 weeks
- 1 decade = 10 years, 1 century = 100 years, 1 millennium = 1,000 years
Why are there 60 minutes in an hour?
The Sumerians and Babylonians counted in base 60, which divides evenly by 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30. Greek astronomers used Babylonian sexagesimal fractions for angles and time, and when mechanical clocks divided the hour in medieval Europe, the "first minute" (pars minuta prima) and "second minute" (pars minuta secunda) of the hour became our minutes and seconds.
The 24-hour day comes from ancient Egypt, where the night was divided into 12 hours marked by rising stars, and the day into 12 hours by sundials. Revolutionary France tried a decimal day of 10 hours of 100 minutes in 1793, but abandoned it after 17 months.
Time units from smallest to largest
Every proportional time unit on the site, ordered by size and expressed in seconds.
- Planck time 5.391247 × 10-44 s
- Yoctosecond 1 × 10-24 s
- Jiffy (physics) 3.3356 × 10-24 s
- Zeptosecond 1 × 10-21 s
- Attosecond 1 × 10-18 s
- Atomic unit of time 2.418884 × 10-17 s
- Femtosecond 1 × 10-15 s
- Svedberg 1 × 10-13 s
- Picosecond 1 × 10-12 s
- Nanosecond 1 × 10-9 s
- Shake 1 × 10-8 s
- Microsecond 0.000001 s
- Millisecond 0.001 s
- Centisecond 0.01 s
- Jiffy (electronics) 0.0166667 s
- Decisecond 0.1 s
- Blink 0.3 s
- Heartbeat 0.8 s
- Decimal second 0.864 s
- Sidereal second 0.99727 s
- Second 1 s
- Nanocentury 3.1557 s
- Helek 3.33333 s
- Vighati 24 s
- Minute 60 s
- Decimal minute 86.4 s
- Swatch beat 86.4 s
- Moment (medieval) 90 s
- Centiday 864 s
- Ke 900 s
- Kilosecond 1,000 s
- Ghati 1,440 s
- Muhurta 2,880 s
- Microcentury 3,155.7 s
- Hour 3,600 s
- Shichen 7,200 s
- Geng 8,640 s
- Decimal hour 8,640 s
- Jupiter day 35,730 s
- Sidereal day 86,164.1 s
- Day 86,400 s
- Kin (Maya) 86,400 s
- Mars sol 88,775.2 s
- Week 604,800 s
- Megasecond 1,000,000 s
- Fortnight 1,209,600 s
- Winal 1,728,000 s
- Draconic month 2,351,140 s
- Tropical month 2,360,580 s
- Sidereal month 2,360,590 s
- Anomalistic month 2,380,710 s
- Synodic month 2,551,440 s
- 30-day month 2,592,000 s
- Month 2,629,750 s
- Dog year 4,508,140 s
- Quarter (year) 7,889,240 s
- Venus day 10,087,200 s
- Semester 15,778,500 s
- Draconic year 29,948,000 s
- Tun (Maya) 31,104,000 s
- Common year 31,536,000 s
- Tropical year 31,556,900 s
- Year 31,557,000 s
- Julian year 31,557,600 s
- Sidereal year 31,558,100 s
- Gaussian year 31,558,200 s
- Anomalistic year 31,558,400 s
- Leap year 31,622,400 s
- Mars year 59,355,100 s
- Triennium 94,670,900 s
- Olympiad 126,228,000 s
- Lustrum 157,785,000 s
- Decade 315,570,000 s
- Indiction 473,354,000 s
- Saros 568,972,000 s
- Metonic cycle 599,582,000 s
- Katun 622,080,000 s
- Score (20 years) 631,139,000 s
- Generation 788,924,000 s
- Gigasecond 1,000,000,000 s
- Jubilee 1,577,850,000 s
- Human lifetime 2,313,120,000 s
- Callippic cycle 2,398,380,000 s
- Century 3,155,700,000 s
- Pluto year 7,824,390,000 s
- Hipparchic cycle 9,593,510,000 s
- Baktun 12,441,600,000 s
- Millennium 31,557,000,000 s
- Sothic cycle 46,105,700,000 s
- Piktun 248,832,000,000 s
- Platonic year 813,302,000,000 s
- Terasecond 1,000,000,000,000 s
- Kalabtun 4,976,640,000,000 s
- Yuga 13,632,900,000,000 s
- Megaannum 31,557,600,000,000 s
- Mahayuga 136,329,000,000,000 s
- Galactic year 7.258248 × 1015 s
- Manvantara 9.679347 × 1015 s
- Gigaannum 3.15576 × 1016 s
- Kalpa 1.363288 × 1017 s
- Age of the universe 4.350846 × 1017 s
All 101 time units
Everyday
- 30-day months
- Centuries
- Common years
- Days
- Decades
- Fortnights
- Hours
- Leap years
- Millennia
- Minutes
- Months
- Quarters (year)
- Scores (20 years)
- Seconds
- Semesters
- Weeks
- Years
Metric (SI)
- Attoseconds
- Centiseconds
- Deciseconds
- Femtoseconds
- Gigaseconds
- Kiloseconds
- Megaseconds
- Microseconds
- Milliseconds
- Nanoseconds
- Picoseconds
- Teraseconds
- Yoctoseconds
- Zeptoseconds
Astronomical
- Anomalistic months
- Anomalistic years
- Callippic cycles
- Draconic months
- Draconic years
- Galactic years
- Gaussian years
- Gigaannums
- Hipparchic cycles
- Julian years
- Jupiter days
- Mars sols
- Mars years
- Megaannums
- Metonic cycles
- Platonic years
- Pluto years
- Saroses
- Sidereal days
- Sidereal months
- Sidereal seconds
- Sidereal years
- Sothic cycles
- Synodic months
- Tropical months
- Tropical years
- Venus days
Scientific
Historical & cultural
- Baktuns
- Centidays
- Decimal hours
- Decimal minutes
- Decimal seconds
- Generations
- Geng
- Ghatis
- Halakim
- Indictions
- Jubilees
- Kalabtuns
- Kalpas
- Katuns
- Ke
- Kin (Maya)
- Lustra
- Mahayugas
- Manvantaras
- Moments (medieval)
- Muhurtas
- Olympiads
- Piktuns
- Shichen
- Swatch beats
- Triennia
- Tun (Maya)
- Vighatis
- Winals
- Yugas
Everyday comparisons
Frequently asked questions
How many seconds are in a day?
86,400 seconds (24 × 60 × 60).
How many seconds are in a year?
A common year of 365 days has 31,536,000 seconds; a leap year has 31,622,400; the average Gregorian year has 31,556,952 seconds.
How many weeks are in a year?
A common year has 52 weeks and 1 day; a leap year has 52 weeks and 2 days. The average Gregorian year is about 52.18 weeks.
How many days are in a month?
Months have 28 to 31 days. The average Gregorian month is 30.436875 days.
What is a leap second?
A leap second is occasionally added to UTC to keep atomic time aligned with the Earth's slightly irregular rotation. 27 have been added since 1972, and they are due to be discontinued by 2035.