the time is taken from the ds system itself, you have to change it there. If your ds is set to start automatically then you'll have to start the system without a game inserted to reach the options menu.
No natural diamond will change colour.
Change the DS time then save your game again on diamond the time in the game will change with the DS time.
yes it will change the time in Pokemon in either Pokemon diamond and pearl.
Edit on your NDS, NDSL or NDSI.
If you mean hour, change the settings on your DS. It will automaticaly change the time on D/P.
Diamond rocks will always be diamonds.
no
Pokemon Diamond was released a tiny bit earlier as it is put first in bulbapedia lists and the creators needed time to change the lengendary from dialga to palkia.
Just change the date on the DS and it'll effect the same as Pokemon Diamond.
You would have to change the date on your DS to change the date on Pokemon Diamond, since the game runs on what time and what day is set on your DS. I wouldn't change it though because that will mess up your game then you'll have to restart the game all over again. (I've tried it and that's exactly what happened to me).
change your ds clock
no but in platinum can