TOP EPOCH SIGN IN SECRETS

Epoch as opposed to equinoxDate-references for coordinate systemsEpochs and periods of validityChanging the common equinox and epochSpecifying an epoch or equinoxBesselian yearsJulian decades and J2000Epoch in the daySee alsoReferencesNotesCitationsSourcesFurther readingExternal backlinksThe principle use of astronomical quantities laid out in in t