help my DS aged nearly 3 has suddenly started waking at 6am

[waitingforgodot]

and will not go back to sleep. As a result, he is lethergic all day and usually needs to have a nap around now.
Any tips?
He has black out blinds in his room so its not the daylight thats waking him.

Does he have black out curtains aswell? Last year I found once it started getting lighter earlier DS was waking up about 5:30-6. He already had blackout curtains but they were still letting the light in around the edges. Blackout blinds used with the curtains stopped this.

I have normal blinds with a black out roller blind over the top so its pretty dark in his room.

Can he read his numbers? We used a cheap clock radio from tescos (£2.99) with a digital display. We set it so that at first it said 7am when it was really 6am and then gradually altered the time in ten minute slots. She got stickers if she waited in her room until the clock read 7-something.

Worked quite well until DS was born and he gets up every day at 5am!!
You can buy the clock with the bunny ears but I think it is quite expensive...

he cant read numbers yet but will maybe get a rabbit clock if it works!

You could just use a night light plugged into a timer switch. Have it on when he goes to bed and set it go off for anytime after you want him to get up. If he wakes up before the light has gone off he has to stay in bed.