IS ERROR with nested if statement

I'm trying to make the the following line

=IF($C$62="",DATE($E$59,$D$59,$C$59), DATE($E$62, $D$62,$C$62))

deal with error handling but i just can't seem to get the sytax for iferror correct. At the moment when C62 and E59,D59,C59 are blank I'm getting the #NUM error.

Thanks for any help