Yes. Leave it on and running for a few hours and it should stop bugging you. I was able to confirm this with a local user who already has his radio (the lucky stiff). Also, interestingly, he's never charged it via USB, so having batteries in it and the scanner on and running is enough to charge the clock battery. No need to leave it plugged in to charge the battery.
I have had mine since last Tuesday and only had to enter the time when I first turned it on. I have had batteries in it and it's been on everyday and cycling through batteries without any trouble. I have never charged the radio through the USB.
I believe UP Man said the batteries will help keep the clock battery charged.