I turned on Valentine's Day about 45 minutes ago. As far as I can tell, I have all the upgrades (six bikkies) and the relevant achievement (Lovely Cookies); I do not have Starlove so there seems no advantage in staying in this season any longer, certainly not the full 24 hours. Everything worth getting can be got in a couple of minutes. Seems a rather inadequate season, rather lacking in interest, especially compared with the first one I happened to try which was the Christmas season.
Maybe I was hoping for something more... but a lot of people have that experience on Valentine's Day I imagine. They hope for something they don't get.