diff --git a/checks/check_extra757 b/checks/check_extra757
index 1ee03f34..7c5a5e95 100644
--- a/checks/check_extra757
+++ b/checks/check_extra757
@@ -17,13 +17,13 @@ CHECK_TYPE_extra757="EXTRA"
 CHECK_ALTERNATE_check757="extra757"
 
 extra757(){
-  OLDAGE="$(date -v -6m '+%Y-%m-%d')"
+  OLDAGE="$(get_date_previous_than_months 6)"
   textInfo "Looking for EC2 instances in all regions..."
   for regx in $REGIONS; do
     textInfo "Looking for EC2 instances in region $regx"
-    INSTACES_OLD_THAN_AGE=$($AWSCLI --region $regx ec2 describe-instances --query "Reservations[].Instances[?LaunchTime<='$OLDAGE'][].{id: InstanceId, launched: LaunchTime}" --output text)
     EC2_RUNNING="$($AWSCLI ec2 describe-instances --region $regx --query "Reservations[*].Instances[*].[InstanceId]" --output text)"
     if [[ $EC2_RUNNING ]]; then
+      INSTACES_OLD_THAN_AGE=$($AWSCLI --region $regx ec2 describe-instances --query "Reservations[].Instances[?LaunchTime<='$OLDAGE'][].{id: InstanceId, launched: LaunchTime}" --output text)
       if [[ $INSTACES_OLD_THAN_AGE ]]; then
         while IFS= read -r ec2_instace
         do
diff --git a/checks/check_extra758 b/checks/check_extra758
index 129047a4..0d1fee22 100644
--- a/checks/check_extra758
+++ b/checks/check_extra758
@@ -17,7 +17,7 @@ CHECK_TYPE_extra758="EXTRA"
 CHECK_ALTERNATE_check758="extra758"
 
 extra758(){
-  OLDAGE="$(date -v -12m '+%Y-%m-%d')"
+  OLDAGE="$(get_date_previous_than_months 12)"
   textInfo "Looking for EC2 instances in all regions..."
   for regx in $REGIONS; do
     textInfo "Looking for EC2 instances in region $regx"
diff --git a/include/os_detector b/include/os_detector
index 1cbb368d..4acbec93 100644
--- a/include/os_detector
+++ b/include/os_detector
@@ -76,6 +76,12 @@ elif [[ "$OSTYPE" == "darwin"* ]]; then
         DAYS_TO=$((( $DATE_IN_DAYS - $TODAY_IN_DAYS )/60/60/24))
         echo $DAYS_TO
       }
+  get_date_previous_than_months()
+      {
+        MONTHS_TO_COMPARE=$1
+        DATE_BEFORE_MONTHS_TO_COMPARE=$(date -v -$(echo $MONTHS_TO_COMPARE)m '+%Y-%m-%d')
+        echo $DATE_BEFORE_MONTHS_TO_COMPARE
+      }
 elif [[ "$OSTYPE" == "cygwin" ]]; then
   # POSIX compatibility layer and Linux environment emulation for Windows
   TEMP_REPORT_FILE=$(mktemp -t -p /tmp prowler.cred_report-XXXXXX)