diff --git a/CHANGELOG.md b/CHANGELOG.md
index e18c6edca8..2ce6c91e71 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Add safety factor sRated calculation [#629](https://github.com/ie3-institute/simona/issues/629)
 - Re-implemented ResultEventListener in akka typed [#343](https://github.com/ie3-institute/simona/issues/343)
+- More expressive failure message upon setting up Primary Service with wrong time pattern [#475](https://github.com/ie3-institute/simona/issues/475)
 
 ### Changed
 - Adapted to changed data source in PSDM [#435](https://github.com/ie3-institute/simona/issues/435)
diff --git a/input/samples/vn_simona/vn_simona.conf b/input/samples/vn_simona/vn_simona.conf
index dfb9dfa903..a92ee4c117 100644
--- a/input/samples/vn_simona/vn_simona.conf
+++ b/input/samples/vn_simona/vn_simona.conf
@@ -28,6 +28,7 @@ simona.input.primary.csvParams = {
   directoryPath: "input/samples/vn_simona/fullGrid"
   csvSep: ","
   isHierarchic: false
+  timePattern: "yyyy-MM-dd'T'HH:mm:ss[.S[S][S]]'Z'"
 }
 simona.input.grid.datasource.id = "csv"
 simona.input.grid.datasource.csvParams = {
diff --git a/src/main/scala/edu/ie3/simona/service/primary/PrimaryServiceWorker.scala b/src/main/scala/edu/ie3/simona/service/primary/PrimaryServiceWorker.scala
index a4b7ee6078..233c85febe 100644
--- a/src/main/scala/edu/ie3/simona/service/primary/PrimaryServiceWorker.scala
+++ b/src/main/scala/edu/ie3/simona/service/primary/PrimaryServiceWorker.scala
@@ -35,8 +35,10 @@ import edu.ie3.simona.service.{ServiceStateData, SimonaService}
 import edu.ie3.simona.util.TickUtil.{RichZonedDateTime, TickLong}
 import edu.ie3.util.scala.collection.immutable.SortedDistinctSeq
 
+import java.io.IOException
 import java.nio.file.Path
 import java.time.ZonedDateTime
+import java.time.format.DateTimeParseException
 import java.util.UUID
 import scala.jdk.CollectionConverters._
 import scala.jdk.OptionConverters.RichOptional
@@ -78,15 +80,30 @@ final case class PrimaryServiceWorker[V <: Value](
         Try {
           /* Set up source and acquire information */
           val factory = new TimeBasedSimpleValueFactory(valueClass, timePattern)
-          val source = new CsvTimeSeriesSource(
-            csvSep,
-            directoryPath,
-            fileNamingStrategy,
-            timeSeriesUuid,
-            filePath,
-            valueClass,
-            factory
-          )
+          val source = Try(
+            new CsvTimeSeriesSource(
+              csvSep,
+              directoryPath,
+              fileNamingStrategy,
+              timeSeriesUuid,
+              filePath,
+              valueClass,
+              factory
+            )
+          ) match {
+            case Failure(exc: DateTimeParseException) =>
+              throw new IOException(
+                s"Could not initiate the time series source. Parsing ${exc.getParsedString} failed with timepattern: $timePattern. The time pattern can be configured in the configuration.",
+                exc
+              )
+            case Failure(exc) =>
+              throw new IOException(
+                s"Could not initiate the time series source.",
+                exc
+              )
+            case Success(source) =>
+              source
+          }
           (source, simulationStart)
         }