Brent,

Welcome to X Marks the Scot first off.

Up until about two weeks ago I had never heard of a a day plaid either. I was informed by some reliable sources that a day plaid is a simple wool tartan square neatly folded and draped over one shoulder. Its purpose is to be there if one needs a blanket (either for warmth or perhaps to sit on). The day plaids won't have a fancy fringe and are not attached with a brooch.

Cheers

Jamie