Meaning
A clock face with both hands pointing straight up at the 12, so they overlap and look like a single hand. Since the dial has no a.m. or p.m., it can mean either noon or midnight.
It marks lunch breaks, midnight deadlines and New Year countdowns, often next to 🍱 or 🎆: “Form closes at 🕛 tonight, not a minute later.” When noon versus midnight really matters, add a word that makes it clear.