In astronomy, an epoch is a moment in time used as a reference point for some time varying astronomical quantity, such as the celestial coordinates or elliptical .Epoch and unix timestamp converter for developers. Date and time function syntax reference for various programming languages..Applications of GPS Provided Time and Frequency and Future Edward Powers United States Naval Observatory GPS Timing Operations Division Chief.Epoch Unix Timestamp Converter. Converts an epoch unix timestamp into a human readable date. It also lets you do the inverse, i.e. converts a human readable date .