To set the clock on the T235, make sure that the radio is off. If the radio is playing, press and hold the Power/Mode (the left-most button) until the display briefly shows Off and the time is displayed. Press and hold the Clock button (the center button), the display should start flashing. While the display is flashing, press the Tun + (Hour) button, next to the Power/Mode button, to advance the hour to the current hour. Then press the Tun - (Minute) button, between the Tun + and Clock buttons, to advance the time to the correct minutes. Then while the display is flashing, press Clock and hold to exit the time set mode. This will start the clock.
Timex has the manuals for many of their clock radios on the product page or their support page,
https://timexaudio.com/support/ . For the T235, the direct link to the manual is
https://timexaudio.com/media/uploads/product/files/T235_User_Manual.pdf . See page 6 to find the directions to set this model.
I hope this helps.
Cindy Wells