Flex has a couple of controls for entering/editing dates, but nothing for time values. I've needed such for a couple of projects in the past and have come across a few after doing a search. Problem is, none of them were exactly what I was looking for.
One of them didn't allow switching between 12 hr and 24 hr time formats, a couple were a bit buggy, and none of them felt very polished in that they didn't match the look & feel of the other SDK components (and were a bit lacking in styling support), had weird focus behavior, and didn't fully support tabbing and keyboard integration among other things.
So I made my own.
Source code located at: https://www.assembla.com/code/shinynet/subversion/nodes/