How do I check if a cron expression executes daily, weekly or monthly?

Question

Is there any easy way to do it other than comparing the characters in the cron expression with all the possible characters?

Answer 1

with help from RC's comment. I came up with this. This will return the difference in days.

String cron = "0 0 12 * * ? *";
CronExpression cronExpression = new CronExpression(cron);
Date date1 = cronExpression.getNextValidTimeAfter(new Date());
Date date2 = cronExpression.getNextValidTimeAfter(date1);
long diff = date2.getTime() - date1.getTime();
long days = TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS);

Answer 2

1. check cron log file

   cat /var/log/sysog | grep CRON

2. create a cron job that write the current time to a file, then evaluate

   */1 * * * * echo $(date) >> cron.log