Thanks for the suggestions all!
Doing a replace would not work, as any occurrences such as 0901 would become 9 1 (char data). But doing WHERE CAST(ActualTime AS INT) <> 0
Excluding any occurrences NOT like '0%'
would skip 0901 (the char data is in military time).
The suggestion that works at the moment is the where ActualTime > '0000'
(has to be 4 zeros to exlude 0, 00, 000 as well as 0000 - again, char data).
The downside is missing anything that midnight, which I never accounted for in my original post, but that is a problem for another day. Unfortunately midnight is 0000 and "no data" can also be represented by 0000, amoung other things (0,00,000 and blank).
Argue for your limitations, and sure enough they're yours (Richard Bach, Illusions)