Why is formula with error?

I would like to make logical formula rule in case 0 values in fields like
H1/H2

I try to do:
=IF(H1>0 *OR H1>0;H1/H2;0)

What is wrong with this logical formula.
Seems OR can not be included in logical rule? *OR
Is this correct?


The same sample issue:
=IF(F16=0;TODAY()-E16;F16-E16)

I like to do in this case AND operator inside formula:
=IF(F16=0 AND E16=0;TODAY()-E16;F16-E16)