Press "P", that's it.
I searched for a previous report of this bug and couldn't find it, but sometimes when I start the game the hotkeys for time acceleration (Num pad 0, 1, 2, and 3) do not work. Restarting the game doesn't fix it, and the only fix I've found so far is a complete reboot of my computer.
Hiya, This is a known bug and restarting should help. However I should add, I sometimes have had to restart twice in a row to get it to work.
The bug is also reported here : http://answers.ea.com/t5/The-Sims-4-Bug-Reports/READ-FIRST-Compiled-list-of-Bugs/m-p/3445209#U3445209
So you might want to keep an eye out on that thread to see if it has gotten fixed or not!
@Athalon020 Merged you in here
