get difference between 2 dates in google script -


i'm trying difference between 2 dates in googlescript. doesn't seem working. seem know why? user defined variables working it's when difference between 2 result 4.28e8 whereas answer supposed 40. there way convert date number convert date?

 ddate = output.getrange(lrow2,2,1,1).getvalue() - output.getrange(2,1,1,1).getvalue() 

function works, difference in milliseconds. interested in conversion, it's follows:

diff = ((output.getrange(lrow2,2,1,1).getvalue() - output.getrange(2,1,1,1).getvalue()) / (1000*60*60*24))

or simply:

days = milliseconds/ (1000*60*60*24)