I use fetchmail every 5 minutes between 05:00 and 23:00 each day and I thought it might be good to suspend the fetches between 12:00 and 13:00 since I run a half-day backup during that time.
The line currently reads */5 5-23 * * * sh -c ". $HOME/.master.env; ./etc/do_mail" I modified it to read */5 5-12,13-23 * * * sh -c ". $HOME/.master.env; ./etc/do_mail" When I tried that line, it still continued to run every 5 minutes between 12:00 and 13:00 and I did check to see if my edit of crontab extended past 12:00. It was at 11:58 so the cron at 11:59 should have been running with the new crontab. In this case, no harm was done but shouldn't the cron runs have stopped at 12:00 and then resumed at 13:00? I guess the */5 criteria is still valid until 12:55 but I thought all of those conditions were anded and the fact that 12,13 specifically means 12:00 and then 13:00, not from 12:00 until 13:00 would cause the */5 specification to stop running. I've only been doing unix for 29 years so I probably should know a lot more but there may someday be a time when this would have been a critical problem so it is good to know now. Martin McCormick WB5AGZ