The results are listed on the left. This shows the future dates and times that a job would run for the crontab command string you entered.
'Run' an empty box to return to the start-up demo.
Reminder of the format... mm hh D M DoW
mm - the minute, a value 0-59
hh - the hour, a value 0-23
D - the day number in the month, 1-31
M - month, 1-12
DoW - day-of-the-week, 0-6 (0 = Sunday)
A '*' in any position means all values.
Multiple values '0,20,40', all in range '0-59'.
Every nth '0-59/n', '*/2' would be every other.
Month can be just the first three letters of the name,
so 'mar,jun,sep,dec' or '3,6,9,12' or '3-12/3'
would all give you quarterly reports.
The Day-of-the-Week can be e.g. 'mon,wed,fri'.
Cron Sandbox & Tutorials
There are many crontab tutorials on the web that offer a more detailed explanation.
Come back here to experiment with the various combinations of crontab parameters.