问题
Does the following cron expression mean "execute every other Sunday?"
0 0 3 ? * 2/1 *
I'm trying to use it with the Spring Quartz scheduler.
回答1:
The expression you are asking about fires at 3 am Monday to Saturday. From the Quartz Javadoc you could try using the two expressions 0 0 3 ? * 1#1 * and 0 0 3 ? * 1#3 * to execute on the 1st and 3rd Sundays of the month. The D#N syntax lets you pick the Nth day D of the month.
回答2:
No, I don't think so. I think "2/1" means "Tuesday through Sunday." I'm not sure that it's possible to express "Every other Sunday", because there'd have to be a "week of month" field or something like that.
来源：https://stackoverflow.com/questions/2819523/does-this-cron-expression-mean-every-other-sunday