What do you do if it’s Saturday and you see the following instructions on a parking meter? “Hours of operation 8 a.m. to 6 p.m. Monday through Friday” and “No fee required Sundays and holidays.”

If you’re reader Alex of Newton, who encountered those messages on a meter on Gloucester Street near Marlborough Street in Boston’s Back Bay, you plug in a quarter for every 12 minutes you plan to stay. “Not a risk-taker, I fed the meter,” he wrote in an e-mail, asking, “So, what is one to conclude about Saturdays?”