Meaning
Eleven o’clock on a clock face, with the minute hand at the 12 and the hour hand just one step to its left at the 11, so the two hands almost close together.
Eleven in the morning is late-morning snack time, and eleven at night is the last call before bed: “Store closes at 🕚, grab milk on your way home.” It also fits late-night study sessions alongside 📚.