I was working on a friend's '91 740 speedometer(classic leaking capacitors) and I noticed the clock doesn't have an adjustment **** poking out of the clear, plastic instrument cover. In fact, I've noticed a few others since then - some have it and some don't. As you can see, the only 2 holes are for the service reset button and the mileage reset button, below the speedo - nothing for the clock. So how do you set the time on these?

 

Those have a switch on the dash to the left of the steering wheel...

 

Great! Found it. Thanks for the tip.