A to Z of Excel Functions: The NOW Function

Welcome back to our regular A to Z of Excel Functions blog.  Today we look at the NOW function.

The NOW function

Dates count from 1 January 1900, e.g. what is known as serial number one [1] is 1 January 1900, serial number two [2] is 2 January 1900, under the default Excel for Windows settings.  The NOW function returns the serial number of the current date and time (the date is an integer at precisely midnight).  If the cell format were General before the function was entered, Excel changes the cell format so that it matches the date and time format of your regional settings.  You can change the date and time format for the cell by using the commands in the Number group of the Home tab on the Ribbon.

This function is useful when you need to display the current date and time on a worksheet or calculate a value based on the current date and time, and have that value updated each time you open the worksheet.

However, should the NOW function not update cell values when you expect it to, you might need to change the relevant settings that control when the workbook or worksheet recalculates. These settings may be changed in File -> Options -> Formulas -> Calculation options.

The NOW function has the following syntax:

The NOW function takes no prisoners or arguments.

It should be noted that:

• Excel stores dates as sequential serial numbers so that 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 39,447 days after January 1, 1900

• numbers to the right of the decimal point in the serial number represent the time; numbers to the left represent the date.  For example, the serial number 0.5 represents the time 12:00 noon

• the results of the NOW function change only when the worksheet is calculated or when a macro that contains the function is run.  It is not updated continuously.

Please see my example below: 

We’ll continue our A to Z of Excel Functions soon.  Keep checking back – there’s a new blog post every business day.

A full page of the function articles can be found here.