Keyboard shortcuts are great time savers, as long as you can remember them.  I recently discovered that Excel uses the top left keys on your keyboard as easy to remember formatting shortcuts for numbers, date, and time.  The shortcuts are as follows:

SHORTCUT KEYS FORMATTING APPLIED

EXAMPLE

CTRL+SHIFT+~ General format.  This is the default format for Excel, so you will only need this one for a cell that has already been formatted differently.
I’m not making it up when I say that most people I talk with on the phone refer to the ~ as “squiggly line”.  So I’ll make its actual name, Tilde, the nerd word of the day.

12345

CTRL+SHIFT+! Number format with 2 decimal places, thousand separator, and minus sign for negative numbers.

12,345.00
-12,345.00

CTRL+SHIFT+@ Time format as H:MM AM/PM

12:34 PM

CTRL+SHIFT+# Date format as DD-MMM-YY

31-Jan-12

CTRL+SHIFT+$ Currency format with 2 decimal places and negatives in parentheses

$12,345.00
($12,345.00)

CTRL+SHIFT+% Percentage format with no decimal places

12%