RecurringJobManager drift over the time

Hello guys,

I found out that over the time passes, a time drift happens.

RecurringJobManager manager = new RecurringJobManager();
manager.AddOrUpdate("myjob", Job.FromExpression(() => DoWork()), $"0 * * * *", TimeZoneInfo.Local);

In the code above, it’s supposed to execute DoWork method on each hour, e.g. 09:00 pm, 10:00 pm, 11:00 pm, etc. What really happens is that it sometimes executes it at 10:00:09 which is not accurate as much as 10:00:00 is. Is that because the cron expression doesn’t include seconds?

It could have something to do with latency from when the job is enqueued to when it begins processing. My guess is that it’s enqueued at 10:00:00 PM, but begins processing at 10:00:09 PM