Julian date from date-time wave

I have date-time wave that shows both the date and time. I want to convert the date into the Julian day, but don't see an easy way to do it. Can someone suggest an easy way to do it?

Thanks

This should give you a start:

//___________________________________________________________________________________________________
// convert from igor time to julian 
Function DateTime2Julian(double DT)
    
    DT+=Date2Secs(-1,-1,-1) // Get UTC
    DT/=86400 // get days since start of igor epoch
    DT+=DateToJulian(1904,01,01) - 0.5  // add julian date from start of igor epoch
 
    Return DT 
end
//___________________________________________________________________________________________________