First - using all caps is considered shouting - please don't do that.
If you reference a blank cell, the value returned will be zero (for
numeric functions) or the null string.
A1: =J10
will display 0 if J10 is blank and A1 us formatted as General. Since
dates in XL are just integer offsets from a base date, 0 is
equivalent to 1/0/1900 (or 12/31/1899) in the 1900 system or
1/1/1904 in the 1904 system.
You can trap this condition using
A1: =IF(J10<>"", J10, "")
which returns the null string instead of zero.