The 5-Second Trick For epoch sign in
Epoch versus equinoxDate-references for coordinate systemsEpochs and periods of validityChanging the regular equinox and epochSpecifying an epoch or equinoxBesselian yearsJulian many years and J2000Epoch on the daySee alsoReferencesNotesCitationsSourcesFurther readingExternal back linksAstronomical portions could be specified in any of various mean