How can I set cron to run certain commands every one and a half hours?

Question

How can I set cron to run certain commands every one and a half hours?

Answer 1

Two lines in the crontab. Along the lines of:

0 0,3,6,9,12,15,18,21 * * * /usr/bin/foo
30 1,4,7,10,13,16,19,22 * * * /usr/bin/foo