It's amazing how many people who call in feel this is something they need to leave a pointless message about (without a name or phone number, of course). So far today I've gotten:
"Oh, I forgot it was a holiday this weekend."
"I guess you're closed today."
"My regular doctor is closed, too".
"It's hot today"
"What time today will you be opening?"
"Since you're closed I'll call back next week."
"Are you completely closed? Or are you seeing patients today?"