Meaning
A clock face showing four o’clock, with the minute hand at the 12 and the hour hand angled down toward the 4, just below the 3 on the right-hand side.
Four in the afternoon is often teatime or the last stretch before work ends, and four in the morning is early-flight or sunrise-hike time: “Alarm set for 🕓, airport by five.” Combine it with ✈️ or ⛰️ to show which kind of four you mean.