where formula_7 is the TCG time expressed as a Julian date (JD). This is just a transformation of the raw count of seconds represented by the variable TCG, so this form of the equation is needlessly complex. The use of a Julian Date specifies the epoch fully. The above equation is often given with the Julian Date for the epoch, but that is inexact (though inappreciably so, because of the small size of the multiplier formula_2). The value is exactly in accord with the definition.