I looking for a function that I could call like the datediff in SQLserver

lnResults=datediff(mi,datetime1,datetime2) -- Return Minutes
lnResults=datediff(yy,datetime1,datetime2) -- Years
lnResults=datediff(hh,datetime1,datetime2) -- Hours
lnResults=datediff(mm,datetime1,datetime2) -- Months

etc..