It is possible to specify the time of day as the number of kiloseconds of elapsed time since midnight. Thus, instead of saying 3:45 p.m. one could say (time of day) 56.7 ks. There are exactly 86.4 ks in one day. However, this nomenclature is rarely used in practice. Scientific decimal time Scientists often record time as decimal. For example, decimal days divide the day into 10 equal parts, and decimal years divide the year into 10 equal parts. Decimals are easier to plot than both (a) minutes and seconds, which uses the sexagesimal numbering system, (b) hours, months and days, which has irregular month lengths. In astronomy, the so-called Julian day uses decimal days centered on Greenwich noon. Seconds in a decimal minute Since there are 60 seconds in a minute, a tenth part represents = 6 seconds. Minutes in a decimal hour Since there are 60 minutes in an hour, a tenth part represents = 6 minutes. Hours in a decimal day Since there are 24 hours in a day, a tenth part represents = 2.4 hours (2 hours and 24 minutes). Length of a decimal year Since there are about 365 days in a year, there are about = 36.5 days in a tenth of a year. Hence the year 2020.5 represents the day 2 July 2020. More exactly, a “Julian year” is exactly 365.25 days long, so a tenth of the year is 36.525 days (36 days, 12 hours, 36 minutes). These values, based on the Julian year, are most likely to be those used in astronomy and related sciences. A Gregorian year, which takes into account the 100 vs. 400 leap year exception rule of the Gregorian calendar, is 365.2425 days (the average length of a year over a 400–year cycle), resulting in 0.1 years being a period of 36.52425 days ( seconds; 36 days, 12 hours, 34 minutes, 55.2 seconds). Other decimal times Numerous individuals have proposed variations of decimal time, dividing the day into different numbers of units and subunits with different names. Most are based upon fractional days, so that one decimal time format may be easily converted into another, such that all the following are equivalent: 0.500 day 5 heures décimales @500.beats Swatch Internet Time (see above) 50.0 kes or cés (centidays) 500 millidays 50.0% time as a percentage of the day 12:00 standard time Some decimal time proposals are based