How to debug cronjobs scheduler?

Hi,
I have a CronJob scheduled as “0 9 * * 1-5”:

clc-samples-output-qwerty 0 9 * * 1-5

but under Jobs I find:

clc-samples-output-qwerty-27922140                   1/1           8s         3h21m
clc-samples-output-qwerty-27923580                   1/1           8s         116m

Why are there two runs today???

How can I activate debug level logging for cronjob scheduler?