There is an error in the instructions in the RH134 8.2, Chapter 2, Section 4 Guided Excercise (Scheduling Recurring User Jobs).
Step 2 instructs the student to: Schedule a recurring job as student that appends the current date and time to /home/student/my_first_cron_job.txt every two minutes between 8 a.m. and 9 p.m. The job must only run from Monday to Friday, not on Saturday or Sunday.
The solution, however, says this:
*/2 08-20 * * Mon-Fri /usr/bin/date >> /home/student/my_first_cron_job.txt
The problem is that the instruction says 9pm and the solution says 20, which is 8pm.
(See the replies, below. This is a mistake in my understanding, which has since been rectified.)
No errors here. Executing times include 08:00,08:02... 20:56,20:58. So no genral problem, slightly problematic is only end points of range: 08.00 and 21:00. Does its should be included or not?
So, in the long run . . . my bad. @Alexandre is correct, having an end time of 20 will include 20:02, 20:04, . . ., 20:58
(Yes, I tested it.)
I can't believe I assumed that 20 was the end time. I suppose the best way to look at it is that any hour that includes 20.
So, thank you @Alexandre