diff --git a/webinput-csv/test.sh b/webinput-csv/test.sh
index 8cf76e8..7bf6ad1 100755
--- a/webinput-csv/test.sh
+++ b/webinput-csv/test.sh
@@ -22,21 +22,23 @@ wget --no-verbose -O - --header "Authorization: $token" http://localhost:1383/ap
 docker exec -ti intelmq intelmqctl stop deduplicator-expert
 docker exec -ti intelmq intelmqctl clear deduplicator-expert-queue
 
-yesterday=$(date --date='yesterday')
+# Use a non ISO-formatted date to test datetime parsing
+yesterday=$(date --rfc-email --date='yesterday')
 wget --no-verbose -O - --header "Authorization: $token" --header "Content-Type: application/json;charset=utf-8" --post-data "{\"timezone\":\"+00:00\",\"data\":[{\"time.source\":\" $yesterday \",\"source.ip\":\"192.168.56.7\",\"source.asn\":\"65537\"}],\"custom\":{\"custom_classification.type\":\"blacklist\",\"custom_classification.identifier\":\"test\",\"custom_feed.code\":\"oneshot\",\"custom_feed.name\":\"oneshot-csv\"},\"dryrun\":true}" http://localhost:1383/api/upload | grep 'lines_invalid": 0'
 
 result=$(docker exec -ti intelmq intelmqctl run deduplicator-expert message get | grep -Ev 'deduplicator-expert|Waiting for a message|time.observation')
-expected_date=$(date --rfc-3339=seconds --date="$yesterday" | tr ' ' T)
+expected_date=$(TZ=UTC date --iso-8601=seconds --date="$yesterday")
 expected="{
-    \"classification.identifier\": \"test\",
-    \"classification.type\": \"test\",
-    \"feed.code\": \"oneshot\",
-    \"feed.name\": \"oneshot-csv\",
-    \"feed.provider\": \"my-organization\",
-    \"source.asn\": 65537,
-    \"source.ip\": \"192.168.56.7\",
-    \"time.source\": \"$expected_date\"
-"
+ \"classification.identifier\": \"test\",
+ \"classification.type\": \"test\",
+ \"feed.code\": \"oneshot\",
+ \"feed.name\": \"oneshot-csv\",
+ \"feed.provider\": \"my-organization\",
+ \"source.asn\": 65537,
+ \"source.ip\": \"192.168.56.7\",
+ \"time.source\": \"$expected_date\"
+ }"
+result=$(echo $result | tr '\r' '\n')
 test "$result" = "$expected"
 
 echo "Webinput CSV tests completed successfully!"