About custom number, date, and time format codes
Custom number formats If a built-in number format is not available to display data the way you want, you can create a custom format.
Format codes You create custom number formats on the datasheet by specifying format codes that describe how you want to display a number, date, time, or text. You can specify up to four sections of format codes. The sections, separated by semicolons, define the formats for positive numbers, negative numbers, zero values, and text, in that order. If you specify only two sections, the first is used for positive numbers and zeros, and the second is used for negative numbers. If you specify one section, all numbers use that format. If you skip a section, include the ending semicolon for that section.
