[BUG] Cronjob executed earlier than expected, and executed twice

[shieldnet]

Describe the bug

What I did

• I registered a cronjob with cron expression with second (0 50 9 * * *) for daily job execution.

// simplified code
var s *gocron.Scheduler = gocron.NewScheduler()
s.CronWithSeconds("0 50 9 * * *").Do(func() {
   // job functions
})
s.StartAsync()

• My program executed for about three days (12/23 19:00 GMT+9 ~ 12/26 16:00 GMT+9)

What actually happened

• Cronjobs which are scheduled on 12/24 09:50:00 and 12/25 09:50:00 executed exactly on expected time.
• But, job schdueled 12/26 09:50:00 suddenly executed on 12/26 09:48:58.906632. and After the earlier job finished, the job scheduled on 12/26 09:50:00 executed twice.
• Only 12/26 09:50:00 job executed twice and earlier than expected.

To Reproduce

• I can not assure that this bug can be reporduced.

Steps to reproduce the behavior:

1. register cronjob with cron expression
2. start async

Version

• go1.18.3

Expected behavior

• Just one execution of cronjob, at 09:50:00 AM (or, a few seconds after schedule).

Additional context

• NA

[yqchilde]

I also have a similar problem. In my project, execution is occasionally triggered twice. This problem exists in v1.18.0.

[fufuok]

Maybe related to #393?

[JohnRoesler]

I ran a cron job every hour on the 30 min mark for a couple days and didn't observe this issue. Is anyone here still seeing it occur?