cal - print a calendar
[XSI] cal [[month] year ]
The cal utility shall write a calendar to standard output using the Julian calendar for dates from January 1, 1 through September 2, 1752 and the Gregorian calendar for dates from September 14, 1752 through December 31, 9999 as though the Gregorian calendar had been adopted on September 14, 1752.
The following operands shall be supported:
- Specify the month to be displayed, represented as a decimal integer from 1 (January) to 12 (December). The default shall be the current month.
- Specify the year for which the calendar is displayed, represented as a decimal integer from 1 to 9999. The default shall be the current year.
The following environment variables shall affect the execution of cal:
- Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.)
- If set to a non-empty string value, override the values of all the other internationalization variables.
- Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments).
- Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error, and informative messages written to standard output.
- Determine the format and contents of the calendar.
- Determine the location of message catalogs for the processing of LC_MESSAGES .
- Determine the timezone used to calculate the value of the current month.
The standard output shall be used to display the calendar, in an unspecified format.
The standard error shall be used only for diagnostic messages.
The following exit values shall be returned:
- Successful completion.
- An error occurred.
Note that:cal 83
refers to A.D. 83, not 1983.
A future version of IEEE Std 1003.1-2001 may support locale-specific recognition of the date of adoption of the Gregorian calendar.
First released in Issue 2.
The DESCRIPTION is updated to allow for traditional behavior for years before the adoption of the Gregorian calendar.