Thanks hun, we've tried that with Ava but it's still quite dark out here by say 6am and we don't mind her coming up then before DP goes to work. She sleeps with her curtains open (thats how she likes it) and will often sleep until say 7am but it's when she wakes at 1am and decides to come upstairs - the other morning it was about 5am and we'd told her she has to stay in bed until morning... she was sobbing in her bed and when i went in she said "it's still dark and i can't tell if it's morning" when i asked why she's crying she said "cos daddy leaves early and it's still dark time"
So if i could set it to 6am and say no problem look the suns up on your clock then it would solve the getting upset at missing daddy... IYKWIM?
The other option then would be to promise Daddy will come in and give her a kiss and a cuddle before he goes to work - even if she's asleep. My uncle (dairy farmer) used to go in to his kids, turn the light on and say good morning before he'd milk the cows (I would have killed him), but the kids got used to it, said good morning and went back to sleep when he left. Then on days Daddy isn't working, she'll sleep til the sun comes up, and on days he's going to work she still gets her kiss and cuddle, and if she comes in to you afterwards, it's ok?

Just another option.