First make sure you have internet by pinging to www.google.com. If you have internet you can use the command "sudo raspi-config" and select option 4. Internationalisation Options. There you can change the configured time zone. This is the easiest way to change the time without having to change config files.
I have connected it to my Sky router but it is still showing the time an hour earlier. But the date is right. Help please?