Flex query works fine from HAC but errors out in code

Hi, I have this in my Flex WHERE clause:

" AND {o:creationtime} > (sysdate-12/24) "

It works fine in HAC but gives this error during runtime (I copied the gen'd SQL from logs)

"Flexiblesearch error: SQL search error : Fail to convert to internal representation query"

I gathered from link text that hybris would not work well with DB SYSDATE, just wondering why the above works via HAC.

Any help would be appreciated, thanks !