it is used to display the calendar of the month
$ cal
displays the whole year calender
$ cal -y
displays last month, current and next month calender
$ cal -3
displays the 1992 calender
cal 1992
displays the specified month's calender in the specified year
$ cal 12 2023
it gives julian theory
$ cal -j
the whole year will be in julian numbers
cal -j 2023
print 2025 calender
cal 2025
julian calender of 2025
cal -j 2025
it i the wrong format of date
cal 08 2025