How to Calculate DATEDIF formula in Excel?

Question

I would like to get the CalculatedValue for the formula =DATEDIF("5/7/2018","6/6/2018","m") .In Excel it returns zero.

I would like to know what process used while calculating the above formula.

Can anyone please let me know the actual process behind getting the month between two dates ?

Answer 1

Use:

=DATEDIF(DATEVALUE("5/7/2018"),DATEVALUE("6/6/2018"),"m")

will return 0

However:

=DATEDIF(DATEVALUE("5/7/2018"),DATEVALUE("6/7/2018"),"m")

will return 1

Answer 2

"5/7/2018" is May 7th, but there is not a full month until June 6th, hence the zero result.
DATEDIF(start_date,end_date,"M") gives the number of complete months in the period.

Please also note that dates in Excel can be tricky, as it depends on your regional settings.
"5/7/2018" could be July 5th (in my region), hence after June 6th, which should give a #NUM error if you use the DATEDIF function.