I have some JSR352 jobs running in Wildfly (which uses JBeret). Some time ago I noticed strange behaviour, and now I drilled it down to something that’s puzzling me.

So far I assumed the job execution start time to be constant. Once the job is started this should no longer change, right? So I assumed this expression to deliver a constant value as long as the jobContext does not refer to another execution id:

BatchRuntime.getJobOperator().getJobExecution(jobContext.getExecutionId()).getStartTime()

Now the puzzling bit: Although the job execution id does not change (I verified), all of a sudden the start time is reported to be different.
This has no impact on the execution itself but the execution time reporting that I added via listeners.

What can be the reasons or conditions that cause the execution’s start time to change?