Last Day Sale

I just came off the street where I passed a sandwichboard sign that read - Wait. Did I just say 'sandwichboard sign'? What the heck does that mean? Does that make any sense at all? I saw a folding 'tent' kind of sign on the sidewalk that read:

LAST

DAY

SALE!

60% OFF!

I had to think about that for a while. It kind of alarmed me. What does that mean exactly? Last Day Sale? In what context is this the last day? I really hate a lack of clarity. It should have read 'Going out of Business Tonight Sale!' or else 'Armageddon Sale!' - whichever is applicable. Now I'm not sure whether or not to call up all my friends and loved ones right away and wish them a final goodbye.

Perhaps they only meant to say 'Last Day OF THE Sale'. I really do hate a lack of clarity.

FWG