If you need to quickly generate a quick monthly calendar from the command line, just type in
Man Page for “CAL”
cal displays a simple calendar. If no arguments are specified, the current month is displayed.
Display single month output. (This is the default.)
Display prev/current/next month output.
Display Sunday as the first day of the week.
Display Monday as the first day of the week.
Display Julian dates (days one-based, numbered from January 1).
Display a calendar for the current year.
Display version information and exit.
Display help screen and exit
A single parameter specifies the year (1 – 9999) to be displayed; note the year must be fully specified: cal 89 will not display a calendar for 1989. Two parameters denote the month (1 – 12) and year.
Three parameters denote the day (1-31), month and year, and the day will be highlighted if the calendar is displayed on a terminal. If no parameters are specified, the current month’s calendar is displayed. A year starts on Jan 1. The first day of the week is determined by the locale. Ten days following that date were eliminated by the reformation, so the calendar for that month is a bit unusual.