Countifs not returning value on >=

For the life of me I can't figure out why the below formula doesn't work.

When I enter G1 in the final criteria, the value is returned =COUNTIFS(post_visits!$D:$D,$B7,post_visits!$H:$H,$D7,post_visits!$F:$F,"<>On-the-Job-Training (OJT)",post_visits!$B:$B,"Closed",post_visits!$C:$C,G1)

but when I add > or >= to the final criteria, it does not return the value. =COUNTIFS(post_visits!$D:$D,$B7,post_visits!$H:$H,$D7,post_visits!$F:$F,"<>On-the-Job-Training (OJT)",post_visits!$B:$B,"Closed",post_visits!$C:$C,">=G1")

$C:$C is a date field as is G1.

Any guesses??

Yea!! ">=" & G1 worked.

Thanks