Making the Time functions update itself Automatically?

Hi,

Just a quick question. How can make the date/time in a Excel spreadsheet to change itself without me having to press enter all the time in order for the time to change. I want the time to change automatically by itself without user intervention.

I have the time formula of the =NOW() function, but the time does not update itself automatically. How can I do this without entering a character and hitting enter?

I am really really really rusty on how to create macros if this envolves using a macro or a VBA code.

Thx.