Where I live, February is a surname. Not widely distributed; back in the day when South
Africa was a
Dutch colony, slaves used to be imported from the
Dutch East Indies (the locals it seems were too intelligent to volunteer as labourers!) and their surnames often related to their month of arrival and/or sale, February and
September are the ones I see most often, or to the ship they arrived in.
This would seem to suggest that February etc might appear here as lnfns. I haven't seen any examples, but that isn't to say there might not be some.
I wouldn't use any month names as given names; I don't even enjoy
April and
June. And though I might use
May as a mn, it would be for family reasons and its bearers on both sides of my family tree got the name when flower names were popular, so I'm guessing the plant, not the month.