Are there any disadvantages to not having the internal clock?

[Petzbreeder]

I've decided to start playing Ruby, Sapphire and Emerald again.

The battery has run dry again, and I don't know what aspects of the game that the lack of the internal clock will affect.

I know it affects berry growth, but I don't know what else.

Will I be unable to access certain areas and be unable to catch certain pokemon? I know I can just play Omega Ruby and Alpha Sapphire instead, but I need to use the original games for a plan that I'm working on.

I want to catch all Pokemon in their native regions, then transfer them all to X and Y. I like breeding in X and Y, so using all the other games to unlock the shiny charm will be a great challenge!

For cross-gen evolutions (i.e. Roselia into Roserade) I'll breed for the base form in the region that the cross-gen evolution was made available and evolve it. That way, Roserade's summary screen will say that it was obtained in Sinnoh.

[sans the skeleton]

for emerald, you'll basically be unable to obtain a shiny pokemon unless you aim to get one in frame perfect time, which is hella difficult. cant remember if that applies to ruby and sapphire as well, but it definitely applies for emerald, at least.

you'll also be unable to get regice and you will be unable to go to mirage island, as both are time-based events. you can basically work around all of these with gameshark, so either you could replace your battery (or get Nintendo to replace it at the cost of your save file, if they still do that) or you could just skip the middle man and use a third-party device, since thats the only other way of getting those things to work.

if you're working on a nuzlocke or something i suppose you could just give yourself an extra encounter in the nearest locations?

[Petzbreeder]

I basically want to catch all of the pokemon in all of the games, then trade them to X and Y.

I will have things set up so that all the pokemon will be obtained in the region they were first made available. For example, once I transfer a Gardevoir and Gallade to X and Y, Gardevoir's summary screen will say that it came from Hoenn. Gallade's will say that it came from Sinnoh. I would have to breed for a Ralts in Diamond and Pearl to get a Sinnoh native one before I evolve it for the summary screen to say it.