Sim Time has always gone by SO fast, that's why we turn off aging for a bit, best way to do it is Age them halfway or most the way through their current Life Cycle, turn off aging and then just do whatever you want to do with them, how fast a day goes doesn't matter much when they aren't aging and feels a lot longer. Don't fall into the trap of stopping from aging permanently though LOL unless... you want to do something with the character like a fake vampire the way some humans are in real life saying they are vampires because they feel it suits them (that would be fun LOL), turn it on again to let them age up to the next Life Stage before turning it off again and when they get to the Elderly Life Stage it's up to you if you want to do more with them.