Calculate the days between two given dates.
$ ./dcal
dt first_date second_date
-h for help
-v for version
$ ./dcal -h
dt first_date second_date
-h for help
-v for version
-f full human read
-s only simple days
-j json style output
$ dcal 2020-01-01 2020-01-02
Year(s) Month(s) Day(s)
0 0 1