How do you set the clock on a 2011 Chevy impala LT? No manual lots of buttons I don't understand

click the clock button to the left of the cd slot and then turn the tuning knob to move it forward or back- then click the clock button again to do the minutes and move with tuning knob, then click clock button again to select either 12hour or 24 hour (military time- example 7pm=1900 hrs). the buttons with numbers on them are to save presets on the radio of your favorite stations- just push and hold the number you want it on after you have tuned it in with the tuning knob until it beeps and then it will be in the memory.

what if the battery when died and I needed a jump start now the clock shows a new time and run but at an hour and a half ahead and can not reset it