White Day (in Japan and other Asian countries), a fairly recent occasion, "celebrated" one month after Valentine's day
Appears to be a direct result of marketing, kind of a mirror image of Valentine's day (Valentine's day is about love and romance, where White day is one month later, when somehow one is obligated to a response, or payback of the Valentine's gift) http://en.wikipedia.org/wiki/White_Day
Payback on White's day is a suggested rule of 2 to 3 times the cost of the previous month's valentine's gift... (really?)
Where does it all stop?
I usually have a response for Valentine's day - on Valentine's day
And, of course, in the US, there's St Patrick's day at about that same time in March. A much more productive day, I think.
Oh wait, 3/14 or 14.3... wasn't that the day that was for a few years back marketed as "a steak and a b...job day", as in to have something nice for the guys? And then a year or two after everyone who had been fans of that theme for that day jumped in the pi (or pie) day bandwagon. Steak and ... pie day. Good, now there's a third alternative
And of course Paddy's day just a few days after.