Why can't I change time and date on my 9720?

I have a Blackberry 9720 inherited from my daughter. It shows the date as 3 days ago and the time 10 hrs 30 minutes ago. This seems to be the device time. I can't change the time displayed because "automatic" is set on the Date and Time screen with a padlock next to it, and I can't unlock it. What do I need to do?

Was the phone from her workplace, or her personal device? I wonder if something is locked down. Is your daughter in the same timezone as you? Normally these types of things are best resolved by doing a security wipe which will in essence make the phone like new.