A Timely Hoist of Signal Flags and Pennants

Today’s puzzler comes to us from Peter Detwiler. “You may remember me as that goofy Sacramento guy who owns a set of signal flags, who’s frustrated by not sailing on the Bay. You ran a couple of my hoists during the early weeks of COVID semi-isolation. I composed a new two-word message for my neighbors, and I wanted to share it with you too. Remember that the shorter flags with the pointy ends (the two on the far right) are ‘repeater’ flags.”

Can you figure it out without scrolling down to check the key to the international flags and pennants? Peter sent this to us in October. It’s a timely message. Does it have to do with Halloween? Día de los Muertos? The changeover from Daylight Saving Time to Standard Time? Or something else?

If you give up, go ahead and scroll down for the key to interpreting the signals.