calendar systems
Year-organizing methods
Calendar systems are methods of organizing time into days, months, and years.
Most track astronomical cycles—the solar year, lunar months, or both.
The Gregorian calendar dominates global commerce and communication, but many cultures maintain traditional systems: the Hebrew calendar, the Islamic calendar, the Chinese calendar.
Some calendars are lunisolar, reconciling moon phases with solar years through periodic adjustments.
- lunarOf the moon
- lunar monthMoon's orbital period
- GregorianNamed for a pope
- JulianRelating to a famous Roman
- solarOf the star
solar year · intercalation · timekeeping · sidereal · Metonic cycle · scheduling · ephemeris · spring equinox · epoch · religious festivals · public holidays · leap year · event coordination · holy days · academic year · almanac · equinox · sundial
calendar systemsclocks
Instruments displaying hours
stopwatches · hourglasses · chronometers · timers · sundials