Months to Shichen (mo to shichen)

1 month equals 365.2425 shichen exactly.

1 month = 365.2425 shichen

How to convert months to shichen

To convert months to shichen, multiply the number of months by 365.2425. This factor is exact. To go the other way, multiply shichen by 0.002737907007 (rounded).

shichen = months × 365.2425

Example: 10 months = 3,652.425 shichen.

Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.

About these units

Month (mo)

CalendarCurrent unit

One twelfth of an average Gregorian year: 30.436875 days. Calendar months actually range from 28 to 31 days.

Month and Moon are cognates, and the unit began as the Moon's cycle of phases, about 29.53 days from one new moon to the next. The trouble is that 12 of these fall short of a solar year, so calendars have had to choose. The Islamic calendar stays purely lunar, so its year is about 11 days shorter than the solar year, while the Hebrew calendar is lunisolar, using a 19-year cycle with an extra month. Even the start of a lunar month is still debated between observing the crescent and calculating it.

Gregorian months are a compromise that drifted far from the Moon. Their lengths run from 28 to 31 days, and this site uses their mean of 30.436875 days, one twelfth of the average year. The names also keep Roman history: September to December preserve the Latin numerals for seven to ten, since they were originally the seventh to tenth months, and Quintilis and Sextilis were renamed for Julius Caesar and Augustus. When a contract says month, check whether it means a calendar month or thirty days.

1 month = 2,629,746 seconds (exactly).

Sources: Wikipedia: Month; Wikipedia: Lunar calendar

Shichen (shichen)

ChineseHistorical unit (no longer in standard use)

The traditional Chinese 'double hour': two hours, twelve per day, each named after an animal of the zodiac.

Chinese clocks did not always count 24 hours. Since the Han dynasty the day has been divided into twelve periods named after the Earthly Branches, each lasting two hours and called a shichen. The first, zi, runs from 23:00 to 01:00 and is linked to the rat, followed by ox, tiger, rabbit, dragon, snake, horse, goat, monkey, rooster, dog and pig. The animal marks the centre of its period, so the horse sits at noon.

The animals were a practical shorthand, since the branch characters were easy to confuse, as the Eastern Han scholar Xu Shen noted. A Sui dynasty Buddhist text even gave each shichen three animals, one for morning, midday and evening. In the figure used here a shichen is exactly one twelfth of a day, or 7,200 seconds. The same twelve branches also name the years of the zodiac cycle.

1 shichen = 7,200 seconds (exactly).

Sources: Wikipedia: Chinese zodiac; Wikipedia: Chinese units of measurement

Related conversions

See all time units.