If you have your tama right in front of you, just do this: Press the middle button (called B_) And then you should see the clock. Then press A and hold it in when you press C (you may need two hands to do it) and then the clock should have stopped and you'll see 'SET' underneath the numbers. Above the black box you'll see either for example 19/9 or 9/19, it depends on if you have a Connection or a Connexion. And the numbers in the black box are in order: hours, minutes and seconds.
If you want to change the time, you scroll through all numbers with A and confirm with B and then you'll pop on to the next numbercombination. And if you feel finished then press B again when you have changed the minutes and then the clock will start ticking again. To go back to your tama, just press B again.
If you don't understand just reply again!