Can't find the PM button my Chevy Impala 2011 clock
You don't need to but if you wanted to change it from 12 hour to 24 hour at say 7pm change it to 1900. Then save it. Go back in and change back to 12 hour then save it all again.
Search Chevrolet Impala Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Chevrolet Impala Experts