This script decreases time by one day for usage events in given workspace.

minusDay.sh

#/bin/bash
if [[ -z "$1" ]] ; then
  echo "This script needs parameter pointing to eclipse workspace"
elif ! [[ -d $1 ]] ; then
  echo "$1 is not a directoryr"
elif ! [[ -d "$1/.metadata/.plugins/org.jboss.tools.usage/events" ]] ; then 
  echo "$1 does not contain .metadata/.plugins/org.jboss.tools.usage/events subdirectory (perhaps JBoss Tools Usage was not allowed?)"
else
  FILES="$1/.metadata/.plugins/org.jboss.tools.usage/events/*"
  for f in $FILES 
  do
    echo "Processing file $f"
    ROW=`sed -n '/d=/p' $f` 			# extract row containing "d=<number>"
    DATE=`echo $ROW | cut -d'=' -f 2` 		# extract number from this row (represents java date in miliseconds)
    NEW_DATE=$(( $DATE - 86400000 )) 		# decrease the number by one day (in miliseconds)
    sed -i '/d=/s/^.*$/d='$NEW_DATE'/' $f 	# write this new number to the same file
  done
fi