calendar:tldr:58f19
This command is using the "calendar" tool with the option "-B" followed by a variable "${7}".
The "calendar" tool is a command-line utility that displays a calendar for a specific month or year.
The option "-B" is used to display the calendar in the "before" format. This format shows the days of the previous month in the first row of the calendar, giving a glimpse of the previous month's dates.
In this command, the variable "${7}" is being used as an argument. It refers to the seventh positional parameter passed to the script or command. The value assigned to this variable will determine the month or year for which the calendar is displayed.
Overall, this command will show a calendar in the "before" format for the month or year specified by the seventh positional parameter.