How to set the clock on a 2006 GMC Savanana just a AM/FM no CD no hour/min buttons

push the set button and then set the time with seek an scan button

According with the Owners Manual:

* Setting the Time for Radios without Radio Data Systems (RDS)
Press and hold the HR or MIN arrow for two seconds. Then press HR until the correct hour appears on the display. Press and hold MIN until the correct minute appears on the display. The time may be set with the ignition on or off.

* Setting the Time for Radios with Radio Data Systems (RDS)
Your radio may have a button marked with an H or HR to represent hours and an M or MN to represent minutes.
Press and hold the hour button until the correct hour appears on the display. Press and hold the minute button until the correct minute appears on the display. The time may be set with the ignition on or off.
To synchronize the time with an FM station broadcasting Radio Data System (RDS) information, press and hold the hour and minute buttons at the same time until RDS TIME appears on the display. To accept this time, press and hold the hour and minute buttons, at the same time, for another 2 seconds. If the time is not available from the station, NO UPDAT will appear on the display.

RDS time is broadcast once a minute. Once you have tuned to an RDS broadcast station, it may take a few minutes for your time to update.


Hope this helps.

Read the owner manual

check page 3-39

Setting the Time
To set the hour, press the clock button. The clock
symbol will appear on the audio display and the hour
number will flash. Then turn the ADJ knob to increase or
to decrease the hour. To set the minutes, press the
clock button again. The minute numbers will flash.
Then turn the ADJ knob to increase or to decrease
the minutes. The time can be set with the ignition on
or off.
To synchronize the time with an FM station broadcasting
Radio Data System (RDS) information, press and
release the clock button to enter the clock set mode,
then press and hold the clock button for three seconds
until UPDATED appears on the display. If the time
is not available from the station, NO TIME UPDATE will
appear on the display.
RDS time is broadcast once a minute. After tuning to an
RDS broadcast station, it may take a few minutes for
the time to update.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Without knowing which radio you have??? I will guess. With the radio OFF, push the SET button, now use the Seek/Scan buttons to change the time. when done, push the set button again.

Page 20 of your owner's manual for PREMIUM AM/FM STEREO/CASSETTE/SINGLE CD:
RDS: (Radio Data System): Press RDS to access the clock mode.
Setting the clock: Press RDS until SELECT HOUR or SELECT MINS is displayed. Press SEL to increase (◄) or decrease (►). Press RDS again to disengage the clock mode.

or

Page 26 for PREMIUM IN-DASH SIX CD SOUND SYSTEM
Setting the clock: Press MENU until SELECT HOUR or SELECT MINS is displayed. Use SEL to manually increase (▲) or decrease (▼) the hours/minutes. Press MENU again to disengage clock mode.

simply turn on radio, then press and hold hr button till the hours are set then the min till it is set..

try to download the manual from herehttp://www.devicemanuals.com/guide/Automobile/GMC/GMC-Sierra-Owner's-Manual-2004-==TVRBNU5UUTQ=.html

if it's the bose head unit, it's clearly displayed under one of the knobs on the left if i recall properly. hour and minute are seperate buttons.

31 sounds about right for a sierra and the clock settings are in the menu. Hit menu then you have a small round knob to advance the hour or you have two small buttons in the lower right hand corner of the radio.