Apple - Insert date & time in latest version of Numbers

Unfortunately, Apple removed that option in the menu bar. However, you can still get the today's date by manually typing it (obviously) or by selecting the cell and typing "=Today", followed by the return key.

You can also type "=Date", followed by the return key. You can then manually select the date there.

Just happened upon this thread looking for an answer to the same question. What I have discovered is to type "= Now." This will give you the current date and time at that moment.

According to Apple (http://help.apple.com/functions/mac/5.0/), you'll need to enter "=NOW()". Not having used Numbers very much, I didn't know you had to enter the () after the word.