next time, better to keep the same PR...

how to test: issue can be tested on collection/tablefilter.php demo by replacing CountryLock with Stat

this PR is bad, a) this does not fix the same issue in other Dt filters (TypeDate, TypeDateTime, TypeTime), b) code of these filters should be deduplicated

@mvorisek Sorry, but I try just to help fixing bugs even if it is not as exhaustive as you would fancy (to your point that PR is "bad"). I think contributing should not be criticised as "bad" or "good". Every contribution identifying or fixing even the most minor bug should be considered "helpful". If you can make it even better, e.g., by even improving code by deduplicating, everyone will appreciate this a lot.

Please check commit for datetime fixing the same issue