Microsoft Office

Using Custom Number Formats 24
Testing Custom Number Formats
When you create a custom number format, don’t overlook the Sample box on the Number tab in the Format
Cells dialog box. This box displays the value in the active cell using the format string in the Type box.
It’s a good idea to test your custom number formats by using the following data: a positive value, a negative
value, a zero value, and text. Often, creating a custom number format takes several attempts. Each time you
edit a format string, it is added to the list. When you finally get the correct format string, access the Format
Cells dialog box one more time and delete your previous attempts.
To make the negative numbers more prominent, you can add a color code to the negative part of the number
format string:
0.00_-;[Red]0.00-
Formatting dates and times
When you enter a date into a cell, Excel formats the date using the system short date format. You can change
this format by using the Windows Control Panel (Regional and Language Options).
Excel provides many useful, built-in date and time formats. Table 24.9 shows some other date and time formats
that you may find useful. The first column of the table shows the date/time serial number.
TABLE 24.9
Useful Built-In Date and Time Formats
Value Number Format Display
39264 mmmm d, yyyy (dddd) July 1, 2007 (Sunday)
39264 “It’s” dddd! It’s Sunday!
39264 dddd, mm/dd/yyyy Sunday, 07/01/2007
39264 “Month: “mmm Month: July
39264 General (m/d/yyyy) 39264 (7/1/2007)
0.345 h “Hours” 8 Hours
0.345 h:mm o’clock 8:16 o’clock
0.345 h:mm a/p”m” 8:16 am
0.78 h:mm a/p”.m.” 6:43 p.m.
CROSS-REF
See Chapter 13 for more information about Excel’s date and time serial number system.
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