Use the Date tab of the Formats dialog box to specify formats for dates, time, or both dates and time in data cells.
Categories -- Specifies the type of date or time format. The available values include the following:
None -- Specifies that date formatting is based on locale settings.
Default -- Specifies that date formatting is based on system administrator settings.
Date -- Displays only date formats for selection in the Type box.
Time -- Displays only time formats for selection in the Type box.
Date & Time -- Displays both date and time formats for selection in the Type box.
Custom -- Displays custom formats, if any exist, in the Type box.
Type box -- Lists formats that are available for selection based on the specified category. If the Custom category is selected and no custom formats have been created, then the Type box is empty until you add a custom format.
Delete button -- Deletes the custom format that is selected in the Type box. You can delete custom formats only.
Edit Type box -- Specifies a custom format, in Oracle Date Format. The best way to construct the format is to insert items from the Insert box. This ensures proper syntax.
Insert box -- Presents correct syntax for parts of custom date or time formats, such as yyyy for a four-digit year format. Correct Oracle Date Format syntax appears in the Edit Type box as you select tokens.
Add button -- Adds the custom format in the Edit Type box to the list in the Type box.