cal [ [month] year]
The cal utility writes a Gregorian calendar to standard output. If the year operand is specified, a calendar for that year is written. If no operands are specified, a calendar for the current month is written.
The following operands are supported:
Specify the month to be displayed, represented as a decimal integer from 1 (January) to 12 (December). The default is the current month.
Specify the year for which the calendar is displayed, represented as a decimal integer from 1 to 9999. The default is the current year.
See environ(5) for descriptions of the following environment variables that affect the execution of cal: LANG, LC_ALL, LC_CTYPE, LC_TIME, LC_MESSAGES, and NLSPATH.
Determine the timezone used to calculate the value of the current month.
The following exit values are returned:
An error occurred.
See attributes(5) for descriptions of the following attributes:
An unusual calendar is printed for September 1752. That is the month 11 days were skipped to make up for lack of leap year adjustments. To see this calendar, type:
cal 9 1752
The command cal 83 refers to the year 83, not 1983.
The year is always considered to start in January.