There was talk about implementing a BG1NPC-like scripts(in BG1 NPC, the player chooses whether to implement 15,30,45,60 or 90 minutes between talks), but I'm not sure anything came out of it. Check NPC IEP on Spellhold Studios, but I'm not sure. You could do the following, though:
- install Flirt Pack and click on Jaheira from time to time, to check whether your romance is still valid;
- google AdvanceRealTime() command, but it's likely to destroy your game(when console is active, and you can AddGold() and CreateItem() at any time, what is the point?);
- if you do remember a mod that helped you with that, tell us: we'd like to know, too.