I have a little peeve I hope you don’t mind my airing. Actually, it’s something I’d love your help in eradicating if you’re game. Maybe if we all do it by example, we can put a decent dent in a common misuse.
I hesitate to pick at this one because I do not wish to criticize those who wish others well. But here goes.
“Happy Belated Birthday.” This is wrong. The birthday is not belated; it comes on the same day each year. It is the wish that is belated, which makes the correct greeting “Belated Happy Birthday.”
I blame card merchants in part for the confusion. Those cardboard markers installed in the stores’ greeting card racks point out Anniversary, Get Well, Birthday and Belated Birthday. What they mean is “belated birthday wishes” but the phrase has become interpreted, annoyingly, as “Happy Belated Birthday.” Even the card designers and manufacturers have slipped into the sloppiness.
If one really wanted to nitpick, “Happy Belated Birthday” purports to take the snoozer off the hook. “My greeting isn’t belated; your birthday is.” That, of course, is silly.
Can we all pledge to stop wishing people a Happy Belated Mother’s Day, Happy Belated Anniversary and Happy Belated Birthday and instead express our wishes belatedly yet correctly?
Of course, remembering on time is nice too.
Word Nymph 
Of course, you could have a happy belated-mother’s day (for those women who chose career first then child-bearing).
Indeed. Or I suppose a belated birthday if your delivery ran past your due date.
That’s always bugged me, too. But I decided that it may be one of those pick-your-battles situations; sometimes I need to just get over my punctu-compulsive self and appreciate the thought!