In crontab, I can use an asterisk to mean every value, or "*/2" to mean every even value.
Is there a way to specify every odd value? (Would something like "1+*/2" work?)
Depending on your version of cron, you should be able to do (for hours, say):
1-23/2
Going by the EXTENSIONS section in the crontab(5) manpage:
Ranges can include "steps", so "1-9/2" is the same as "1,3,5,7,9".
For a more portable solution, I suspect you just have to use the simple list:
1,3,5,7,9,11,13,15,17,19,21,23
But it might be easier to wrap your command in a shell script that will immediately exit if it's not called in an odd minute.
Every odd minute would be:
1-59/2 * * * *
Every even minute would be:
0-58/2 * * * *
Try
1-23/2
From your question, I'm assuming Vixie Cron. I doubt this will work with any other cron.
As I read the manual "1-23/2" (for hours) would do the trick.
Works on Cronie Even with 5 minutes interval e.g.
3-58/5 * * * * /home/test/bin/do_some_thing_every_five_minute
I realize this is almost 10 years old, but I was having trouble getting 1-23/2 for an every two hour, odd hour job.
For all you users where, exact odd hour precision is not needed. I did the following which suited my teams needs.
59 */2 * * *
Execute the job every two hours, at the 59th Minute.
来源：https://stackoverflow.com/questions/122483/specifying-all-odd-values-in-crontab