On an environment with scheduled Endpoint Discovery scans, the DebugDump.txt logs fill with messages such as the following prior to the scan:
NONE [02/03/2018 16:59:59.990] (WSDLP) CWDiscovery[TID:4376]: Warning!!!!!! - Got invalid local time
NONE [02/03/2018 17:00:00.490] (WSDLP) CWDiscovery[TID:4376]: begin to start JobCrawler, JobID ==> [...]
This happens consistently starting at midnight on the day that the scheduled scan is set to occur until the time of the scan itself.