To find dialga in time you must go too the special tower once you have beaten him the first time around. I think the towers name is temporal tower. To find palkia go to The Spacial place. Dialga is at level 47 so go easy on him, I suggest you bring level 50 - 60's.
Dialga is at the top of Temporal Tower.After some time,Palkia will appear and it will take you to the spatial rift.I recommend that for both Dialga and Palkia,you bring lots of reviver seeds and lots of sleep seeds to throw at them(don't throw the reviver seeds).
NO ONLY ONCE...VERONICA
You can find dialga in the pillar, but I don't know where the pillar is because it was a long time ago when i got dialga.
defeat dialga and defeat wigglytuff and go to luminus springs
find it
you find dialga in mount coronet
you do not find dialga in Pokemon pearl
The best partner is probably charmander because of the killer STAB moves. Plus its very good against dialga which is hard to beat especially with roar of time.
==ansewer== no you do not find dialga in snowpoint city
no you can only find dialga in dimind
u find him in the same place as the first time if not go to wayward cave.
you can find dialga at the top of mount . cornet at spear piller in the diamond game.