Update README.md

Author: SDanS

README.md

@@ -21,7 +21,7 @@ Here you must pass a list of issues to the --issues param ( can be 1 long ) and
 
 perl ~/Scripts/Timeline/sprint_to_timeline.pl --username "username" --password "password" --issues 'KEY-1758' 'KEY-1456' --dir_name TEST2 --start_date 2015 11 06 0 0 --end_date 2015 11 20 0 0
 
-end_date and start_date are optional params. They are used to scale the timelines to a certain scale. Events that occur after the end date or before the start date should be dropped from the timeline. Format is "yyyy mm dd hh mm".
+end_date and start_date are not optional params. They are used to scale the timelines to a certain scale. Events that occur after the end date or before the start date should be dropped from the timeline. Make these ridiculous in order to get whole issue history (will fix). Format is "yyyy mm dd hh mm".
 
 The rest is pretty self-explanatory.