Thanks for the responses guys. The thing I should have mentioned is
that "OC" is actually a sheet name. So essentially with the statement:
IF(OC!I3:I9999<OC!Date(2007,6,6),0) I'm trying to say that "If the
date in column I on sheet OC is less than June 6, 2006.... as a
condition.

We know that... but a "date" does not have a sheet reference... it is just a
date (actually, a number). Change your comparisons form this...

OC!I3:I9999<OC!Date(2007,6,6)

to this...

OC!I3:I9999<Date(2007,6,6)

Note there is no 'OC!' in front of the Date function, only in front of the
cell reference.

Rick