Returns the current date and time.
Time values are a part of a date value and are represented by a decimal number (for example, 12:00 PM is represented by 0.5 because it is exactly halfway through a day).
Excel stores dates as sequential serial numbers so they can be used in calculations. By default, January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900.
If the cell format was General before the function was entered, the result changes the cell formatting to Date.To view the result as a serial number, select the cell, and then on the View menu, click Formatting Palette. Under Number, on the Format pop-up menu, click Number.
The NOW function changes only when the sheet is calculated or when a macro that contains the function is run. It is not updated continuously.