If you scroll all the way to the bottom, it hints at when the quests will end:

Replays of these quests, as well as the temporary stores associated, will be available until [b]Sunday at 11:59pm [b](Paris Hour).

So, normally new quests come out on Monday and last until the end of Sunday, but these didn't last that long because they came out on Wednesday (since the date says Feb. 9). Which would mean the recent Valentine's quests lasted as long as they were supposed to; with 'new' content for Valentine's Day, Feb. 14.

Too bad they couldn't have went ahead and let those Valentine quests last seven days, even if it ended not on a Sunday.