You can turn aging on and off using a simple code.
To turn aging off:
1.
Press and hold down the Ctrl, Shift, and 'c' keys on your keyboard, then release the keys. This should bring up a line at the top of your screen where you can enter text.
2.
In the text box type the word 'aging' and then add a space and then type a minus sign and the word 'off'.
3.
Hit the enter key.
You Sims will no longer age. They will still have an aging bar that tells you how many Sims days must pass before they age, but this timer will be stopped until aging is turned back on. This will also prevent children from growing up, so keep this in mind when you choose to turn aging off.
To turn aging on (after it has been turned off):
1.
Press and hold down the Ctrl, Shift, and 'c' keys on your keyboard, then release the keys. This should bring up a line at the top of your screen where you can enter text.
2.
In the text box type the word 'aging' and then add a space and then type a minus sign and the word 'on'.
3.
Hit the enter key.
Your Sims will now age normally. If aging was stopped, it will now continue from where each Sim's aging timer left off.