No, there is no aging in Realms III. I've never programmed age in any of the RPG games that I've made -- I assume a very abstract timeline where the adventure takes place where aging is not really a factor. A funny thing is that in the SSI gold box games, age is used, but only when casting certain spells (such as haste)--I once tried to camp my party for 365 consecutive days and none of the characters in my party aged at all.

I know that Wizardry and Oubliette employs aging when you rest at the inn -- which adds an extra element of difficulty.

Also in Realms IIIl, there's no need for keeping track of logistical supplies such as food, lighting, etc. The game assumes that an adventuring party is well-equipped. There is ammunition, but it's simplified where the party shares ammo in a common pool (sling bullets and arrows). While it's fairly easy to rest at an inn when you're traveling on the surface -- when you're trapped several floors deep in a dunjon and you're low on spell points, you get a real sense of urgency.