solar year
Earth's full orbit
A solar year is the time it takes Earth to complete one orbit around the sun—approximately 365.25 days.
This is the basis for the calendar year, with the extra quarter-day accumulating into a leap day every four years.
Also called a tropical year or astronomical year.
Sun as orbital center
- eclipticSun's apparent annual path
- solsticeDay of maximum tilt
- equinoxSun crosses celestial midline
- perihelionOrbital point nearest sun
aphelion · sidereal · synodic · precession · axial tilt · obliquity · celestial equator · zodiac
Recoiling metal spiral
- summerYear's warmest season
- autumnPost-summer cooling period
- winterYear's coldest quarter
- solsticeDay of maximum tilt
equinox · vernal · harvest · midsummer · midwinter · growing season · frost · thaw
Length of existence
- chronologyTemporal ordering of events
- annualOccurring every year
- epochDistinct historical period
- eraDistinct historical period
century · millennium · decade · temporal · chronometer · horology · measurement · periodicity
heliocentric
Sun as orbital center
perihelion · aphelion · sidereal · synodic · precession · axial tilt · obliquity · celestial equator · zodiac · celestial sphere
spring
Recoiling metal spiral
solstice · equinox · vernal · harvest · midsummer · midwinter · growing season · frost · thaw · bloom
duration
Length of existence
- chronologyTemporal ordering of events
- annualOccurring every year
- epochDistinct historical period
era · century · millennium · decade · temporal · chronometer · horology · measurement · periodicity · cycle
Gregorian
Named for a pope
- JulianRelating to a famous Roman
- intercalationInsertion between existing elements
- monthsYear's twelve parts
January · February · March · April · May · June · July · August · September · October
- timekeepingclock, watch, watches, clocks, timer
- time conceptsclock, calendar, hour, minute, second
- celestial cycleslunar cycle, lunar phase, orbit, eclipse, solstice
- time cyclesseasonal cycle, yearly cycle, seasons, day, day and night
- time periodsday, month, week, hour, minute
- time unitssecond, minute, hour, seconds, day
solar yearlunar year
Time measured by moons
lunar calendar · lunar month · Islamic calendar · lunar cycle · lunation
year, solar, sol, solarium, solarize, solarization, solarized, solarizing