epoch sign in for Dummies
Epoch vs . equinoxDate-references for coordinate systemsEpochs and intervals of validityChanging the regular equinox and epochSpecifying an epoch or equinoxBesselian yearsJulian yrs and J2000Epoch from the daySee alsoReferencesNotesCitationsSourcesFurther readingExternal hyperlinksThe main usage of astronomical portions specified in this way will b