- Day redirects here. For the Bajoran Field Colonel, see Day Kannu.
One Earth year is equal to 365.2425 Earth days in the Gregorian calendar. To compensate for the fraction of a day, a leap day is added to every year whose number is divisible by four, unless it is a century, unless it is divisible by 400. These leap years consist of adding an extra day to the month of February. Instead of the usual 28 days, there would be 29.
Scientists usually use a Julian year of 365.25 days for measurements and scientific comparisons.
The mean solar year was 365.242190419 days in 2000 AD, and will be shorter still by the 23rd century.
A month is usually the amount of time it takes for a moon to orbit its planet. This is usually a portion of a year, and a large number of days (in which case it may be broken down into weeks).
On Earth a month was originally the length of the lunar cycle (29.53 days). Most calendars at some point made the month one twelfth of a solar year (30.44 days). In Earth's most common calendar, the months are either 30 or 31 days long, with one shorter month (February) having 28 or 29 days depending on the year.
|Months of the year|
|Earth months: January • February • March • April • May • June • July • August • September • October • November • December|
|Qo'noS months: Maktag • nay'Poq|
|Vulcan months: Tasmeen|
A week is small number days grouped together as part of a calendar system. It could be a portion of a month or an unrelated grouping.
On Earth a week is seven days.
|The days of the Human week|
|Sunday • Monday • Tuesday • Wednesday • Thursday • Friday • Saturday|
A day is the amount of time it takes for a planet to spin once on it own axis. This results in a day/night cycle (with day in this second case meaning the sunlit portion of the full day).
On Earth, a full day is divided up into 24 hours, whereas on Bajor, a full day is divided into 26 Hours.
An hour is a portion of a day, this could be a decimal tenth of a day, or some other fractional portion of a day.
A minute is a portion of an hour, this could be a decimal hundredth of an hour, or some other fractional portion of an hour.
On Earth a minute is 1/60 of an hour, and is divided up into 60 seconds.
In colloquial speech, a minute can also mean an undefined short amount of time, as in "I'll be just a minute".
A second is a portion of a minute, this could be a decimal hundredth of a minute, or some other fractional portion of a minute.
On Earth a second is 1/60 of a minute, and is usually divided up decimally.
A nanosecond is one billionth of a second.
Main article: Stardate
In the 23rd century, stardates were not directly related to Earth's calendar. Beginning in 2323, stardates were changed to be 1,000 per Earth year, .