I saw the teaser to "It Happen on Valentine's Day" towards the end of the last episode of "Unhappy Birthday", but there's no airing date yet.
Apparently One31 has decided to rerun "Wanthong" from Wednesdays to Saturdays starting January 5th. Either they're moving this to a later timeslot (9:30PM) as the "Suea Gayng Chanee" sitcom has just finished its run last Friday. Or they're probably airing this around February, premiering at the same time as the next new drama lineup of the channel.