Most of the amswers so far seem to be suggesting this is a southern counties practice, does that seem about right?

I've heard of the "Rabbits" thing, tnough it hasn't been in common use anywhere I have lived (Midlands, N.Lincs & all 3 Yorkshire Ridings). I first came across it in the novels of Dornford Yates.

April 1st has its own rituals, tricks until noon seems widespread, but how far does "legging-down" (also known as legging-up, but its the same thing) reach?