Epoch as opposed to equinoxDate-references for coordinate systemsEpochs and intervals of validityChanging the typical equinox and epochSpecifying an epoch or equinoxBesselian yearsJulian decades and J2000Epoch of your daySee alsoReferencesNotesCitationsSourcesFurther readingExternal hyperlinksAstronomical portions can be specified in any of a numbe… Read More