Excel 2007 : Question regarding a formula

[debronovich]

Hi,
I have a formula that displays the number of months between two dates
=DATEDIF(D4,A1,"m")
It works fine, however data will be added over time and in cells that have no date inputted the formula assumes the date to be 01/01/1900 and gives a ridiculous number. To prevent confusion in others who be using this sheet. How can ensure that no result is displayed until a date has been inputted.

Thanks in advance


a b c d e

1 Surname Forname D.O.B Date of Discharge 12 / 24 Months
2 Boyle John 01/01/1980 01/07/2010 11
3 Boyle Ted 05/10/1984 31/12/200 9 17
4

[daddylonglegs]

Try like this

=IF(D4="","",DATEDIF(D4,A$1,"m"))

[debronovich]

Excellent, thank you so much :-)