How do you extract a timestamp from message having
event1: Timestamp:2018-09-06T00:00:11.214000000, Timezone:UTC
event2: Timestamp:2018-09-06T00:00:11.214, Timezone:CST
where sub seconds can be milliseconds or nano seconds which vary and time zone can be any string like UTC,CST etc.
If you have multiple timestamp formats in single log file, then try configuring datetime.xml. Refer to below docs for more information.