EPOCH SIGN IN - AN OVERVIEW

Epoch versus equinoxDate-references for coordinate systemsEpochs and durations of validityChanging the normal equinox and epochSpecifying an epoch or equinoxBesselian yearsJulian years and J2000Epoch with the daySee alsoReferencesNotesCitationsSourcesFurther readingExternal backlinksThe key use of astronomical quantities laid out in this way should