The Clock on a 2542 not only shows the time of day, it has a built-in timer and alarm. The clock has the ability to control the radio on the 2542. Set the count-down timer for up to 60 minutes and the radio will play for that amount of time. Set the "Alarm" hand on the clock and the control to Alarm and not only will the clocks buzzer sound, the radio will turn on as well.
If the clock looks familiar to you, it should. The clock mechanism is a fairly common assembly used on many stoves and ovens from that time. The clock was made by the General Time Company and they made clock units for appliances and clock radios.