diff --git a/CHANGELOG.md b/CHANGELOG.md
index 37ef1d290..3abd7d730 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Adding timeseries for voltage values [#1128](https://github.com/ie3-institute/PowerSystemDataModel/issues/1128)
 - Added Staudt to list of reviewers [#1190](https://github.com/ie3-institute/PowerSystemDataModel/issues/1190)
 - Extend ValidationUtils for validating ThermalGrids [#1216](https://github.com/ie3-institute/PowerSystemDataModel/issues/1216) 
+- Enhance `TimeSeriesSource` with method to retrieve the previous value before a given key [#1182](https://github.com/ie3-institute/PowerSystemDataModel/issues/1182)
 
 ### Fixed
 - Removing opened `SwitchInput` during connectivity check [#1221](https://github.com/ie3-institute/PowerSystemDataModel/issues/1221)
diff --git a/src/main/java/edu/ie3/datamodel/io/source/TimeSeriesSource.java b/src/main/java/edu/ie3/datamodel/io/source/TimeSeriesSource.java
index a9ade054e..2a80e0a78 100644
--- a/src/main/java/edu/ie3/datamodel/io/source/TimeSeriesSource.java
+++ b/src/main/java/edu/ie3/datamodel/io/source/TimeSeriesSource.java
@@ -50,7 +50,9 @@ protected Try<TimeBasedValue<V>, FactoryException> createTimeBasedValue(
   public abstract IndividualTimeSeries<V> getTimeSeries(ClosedInterval<ZonedDateTime> timeInterval)
       throws SourceException;
 
-  public abstract Optional<V> getValue(ZonedDateTime time) throws SourceException;
+  public abstract Optional<V> getValue(ZonedDateTime time);
+
+  public abstract Optional<TimeBasedValue<V>> getPreviousTimeBasedValue(ZonedDateTime time);
 
   /**
    * Method to return all time keys after a given timestamp.
diff --git a/src/main/java/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSource.java b/src/main/java/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSource.java
index 1bbab427a..0210b7dde 100644
--- a/src/main/java/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSource.java
+++ b/src/main/java/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSource.java
@@ -128,6 +128,15 @@ public Optional<V> getValue(ZonedDateTime time) {
     return timeSeries.getValue(time);
   }
 
+  @Override
+  public Optional<TimeBasedValue<V>> getPreviousTimeBasedValue(ZonedDateTime time) {
+    return timeSeries.getPreviousTimeBasedValue(time);
+  }
+
+  public Optional<TimeBasedValue<V>> getNextTimeBasedValue(ZonedDateTime time) {
+    return timeSeries.getNextTimeBasedValue(time);
+  }
+
   @Override
   public List<ZonedDateTime> getTimeKeysAfter(ZonedDateTime time) {
     return timeSeries.getTimeKeysAfter(time);
diff --git a/src/main/java/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSource.java b/src/main/java/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSource.java
index c75e8b949..7016feb5d 100644
--- a/src/main/java/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSource.java
+++ b/src/main/java/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSource.java
@@ -48,6 +48,7 @@ public class SqlTimeSeriesSource<V extends Value> extends TimeSeriesSource<V> {
 
   private final String queryTimeInterval;
   private final String queryTimeKeysAfter;
+  private final String queryForValueBefore;
   private final String queryTime;
 
   public SqlTimeSeriesSource(
@@ -63,15 +64,16 @@ public SqlTimeSeriesSource(
     final ColumnScheme columnScheme = ColumnScheme.parse(valueClass).orElseThrow();
     this.tableName = sqlDataSource.databaseNamingStrategy.getTimeSeriesEntityName(columnScheme);
 
+    String schemaName = sqlDataSource.schemaName;
+
     String dbTimeColumnName =
         sqlDataSource.getDbColumnName(factory.getTimeFieldString(), tableName);
 
-    this.queryFull = createQueryFull(sqlDataSource.schemaName, tableName);
-    this.queryTimeInterval =
-        createQueryForTimeInterval(sqlDataSource.schemaName, tableName, dbTimeColumnName);
-    this.queryTimeKeysAfter =
-        createQueryForTimeKeysAfter(sqlDataSource.schemaName, tableName, dbTimeColumnName);
-    this.queryTime = createQueryForTime(sqlDataSource.schemaName, tableName, dbTimeColumnName);
+    this.queryFull = createQueryFull(schemaName, tableName);
+    this.queryTimeInterval = createQueryForTimeInterval(schemaName, tableName, dbTimeColumnName);
+    this.queryTimeKeysAfter = createQueryForTimeKeysAfter(schemaName, tableName, dbTimeColumnName);
+    this.queryForValueBefore = createQueryForValueBefore(schemaName, tableName, dbTimeColumnName);
+    this.queryTime = createQueryForTime(schemaName, tableName, dbTimeColumnName);
   }
 
   /**
@@ -179,6 +181,14 @@ public Optional<V> getValue(ZonedDateTime time) {
     return Optional.of(timeBasedValues.stream().toList().get(0).getValue());
   }
 
+  @Override
+  public Optional<TimeBasedValue<V>> getPreviousTimeBasedValue(ZonedDateTime time) {
+    return getTimeBasedValueSet(
+            queryForValueBefore, ps -> ps.setTimestamp(1, Timestamp.from(time.toInstant())))
+        .stream()
+        .max(TimeBasedValue::compareTo);
+  }
+
   @Override
   public List<ZonedDateTime> getTimeKeysAfter(ZonedDateTime time) {
     return dataSource
@@ -278,8 +288,30 @@ private String createQueryForTimeKeysAfter(
   }
 
   /**
-   * Creates a basic query to retrieve an entry for the given time series uuid and time with the
-   * following pattern: <br>
+   * Creates a base query to retrieve all time keys after a given time for given time series with
+   * the following pattern: <br>
+   * {@code <base query> WHERE time_series = $timeSeriesUuid AND <time column> < ?;}
+   *
+   * @param schemaName the name of the database schema
+   * @param tableName the name of the database table
+   * @param timeColumnName the name of the column holding the timestamp info
+   * @return the query string
+   */
+  private String createQueryForValueBefore(
+      String schemaName, String tableName, String timeColumnName) {
+    return createBaseQueryString(schemaName, tableName)
+        + WHERE
+        + TIME_SERIES
+        + " = '"
+        + timeSeriesUuid.toString()
+        + "' AND "
+        + timeColumnName
+        + " < ?"
+        + "ORDER BY time DESC LIMIT 1;";
+  }
+  /**
+   * Creates a base query to retrieve all time keys before a given time for given time series with
+   * the following pattern: <br>
    * {@code <base query> WHERE time_series = $timeSeriesUuid AND <time column>=?;}
    *
    * @param schemaName the name of the database schema
diff --git a/src/main/java/edu/ie3/datamodel/models/timeseries/individual/IndividualTimeSeries.java b/src/main/java/edu/ie3/datamodel/models/timeseries/individual/IndividualTimeSeries.java
index 0b26a1090..a89e1a234 100644
--- a/src/main/java/edu/ie3/datamodel/models/timeseries/individual/IndividualTimeSeries.java
+++ b/src/main/java/edu/ie3/datamodel/models/timeseries/individual/IndividualTimeSeries.java
@@ -55,14 +55,14 @@ public Optional<V> getValue(ZonedDateTime time) {
   @Override
   protected Optional<ZonedDateTime> getPreviousDateTime(ZonedDateTime time) {
     return timeToValue.keySet().stream()
-        .filter(valueTime -> valueTime.compareTo(time) <= 0)
+        .filter(valueTime -> valueTime.compareTo(time) < 0)
         .max(Comparator.naturalOrder());
   }
 
   @Override
   protected Optional<ZonedDateTime> getNextDateTime(ZonedDateTime time) {
     return timeToValue.keySet().stream()
-        .filter(valueTime -> valueTime.compareTo(time) >= 0)
+        .filter(valueTime -> valueTime.compareTo(time) > 0)
         .min(Comparator.naturalOrder());
   }
 
diff --git a/src/main/java/edu/ie3/datamodel/models/timeseries/repetitive/LoadProfileInput.java b/src/main/java/edu/ie3/datamodel/models/timeseries/repetitive/LoadProfileInput.java
index d4450568b..017e28c02 100644
--- a/src/main/java/edu/ie3/datamodel/models/timeseries/repetitive/LoadProfileInput.java
+++ b/src/main/java/edu/ie3/datamodel/models/timeseries/repetitive/LoadProfileInput.java
@@ -42,13 +42,13 @@ public PValue calc(ZonedDateTime time) {
   @Override
   protected Optional<ZonedDateTime> getPreviousDateTime(ZonedDateTime time) {
     // dummy value
-    return Optional.of(time.minusHours(1));
+    return Optional.of(time.minusMinutes(15));
   }
 
   @Override
   protected Optional<ZonedDateTime> getNextDateTime(ZonedDateTime time) {
     // dummy value
-    return Optional.of(time.plusHours(1));
+    return Optional.of(time.plusMinutes(15));
   }
 
   @Override
diff --git a/src/test/groovy/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSourceIT.groovy b/src/test/groovy/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSourceIT.groovy
index 78ca34d74..49b1ce59c 100644
--- a/src/test/groovy/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSourceIT.groovy
+++ b/src/test/groovy/edu/ie3/datamodel/io/source/csv/CsvTimeSeriesSourceIT.groovy
@@ -85,4 +85,24 @@ class CsvTimeSeriesSourceIT extends Specification implements CsvTestDataMeta {
     actual.present
     actual.get() == PH_VALUE_15MIN
   }
+
+  def "A csv time series source is able to return the previous value for a given time"() {
+    when:
+    def actual = source.getPreviousTimeBasedValue(TIME_15MIN)
+
+    then:
+    actual.isPresent()
+    actual.get().time == TIME_00MIN
+    actual.get().value == PH_VALUE_00MIN
+  }
+
+  def "A csv time series source is able to return the next value for a given time"() {
+    when:
+    def actual = source.getNextTimeBasedValue(TIME_00MIN)
+
+    then:
+    actual.isPresent()
+    actual.get().time == TIME_15MIN
+    actual.get().value == PH_VALUE_15MIN
+  }
 }
\ No newline at end of file
diff --git a/src/test/groovy/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSourceIT.groovy b/src/test/groovy/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSourceIT.groovy
index 2b28fbb8c..0b960aba9 100644
--- a/src/test/groovy/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSourceIT.groovy
+++ b/src/test/groovy/edu/ie3/datamodel/io/source/sql/SqlTimeSeriesSourceIT.groovy
@@ -12,6 +12,7 @@ import edu.ie3.datamodel.io.connectors.SqlConnector
 import edu.ie3.datamodel.io.naming.DatabaseNamingStrategy
 import edu.ie3.datamodel.io.naming.timeseries.ColumnScheme
 import edu.ie3.datamodel.io.naming.timeseries.IndividualTimeSeriesMetaInformation
+import edu.ie3.datamodel.models.timeseries.individual.TimeBasedValue
 import edu.ie3.datamodel.models.value.*
 import edu.ie3.test.helper.TestContainerHelper
 import edu.ie3.util.TimeUtil
@@ -123,6 +124,21 @@ class SqlTimeSeriesSourceIT extends Specification implements TestContainerHelper
     value.get() == P_VALUE_00MIN
   }
 
+  def "A SqlTimeSeriesSource is able to return the previous value for a given time"() {
+    when:
+    def actual = pSource.getPreviousTimeBasedValue(time)
+
+    then:
+    actual.isPresent() == expectedResult.isPresent()
+    actual == expectedResult
+
+    where:
+    time       | expectedResult
+    TIME_00MIN | Optional.empty()
+    TIME_15MIN | Optional.of(new TimeBasedValue<>(TIME_00MIN, P_VALUE_00MIN))
+    TIME_30MIN | Optional.of(new TimeBasedValue<>(TIME_15MIN, P_VALUE_15MIN))
+  }
+
   def "A SqlTimeSeriesSource can read multiple time series values for a time interval"() {
     given:
     def timeInterval = new ClosedInterval(TIME_00MIN, TIME_15MIN)
diff --git a/src/test/groovy/edu/ie3/datamodel/models/timeseries/IndividualTimeSeriesTest.groovy b/src/test/groovy/edu/ie3/datamodel/models/timeseries/IndividualTimeSeriesTest.groovy
index a8e569ccf..1adb2a40e 100644
--- a/src/test/groovy/edu/ie3/datamodel/models/timeseries/IndividualTimeSeriesTest.groovy
+++ b/src/test/groovy/edu/ie3/datamodel/models/timeseries/IndividualTimeSeriesTest.groovy
@@ -72,7 +72,7 @@ class IndividualTimeSeriesTest extends Specification implements TimeSeriesTestDa
     Optional<TimeBasedValue<IntValue>> expected =  Optional.of(new TimeBasedValue<>(ZonedDateTime.of(1990, 1, 1, 0, 0, 0, 0, ZoneId.of("UTC")), new IntValue(3)))
 
     when:
-    Optional<TimeBasedValue<IntValue>> actual = individualIntTimeSeries.getPreviousTimeBasedValue(ZonedDateTime.of(1990, 1, 1, 0, 0, 0, 0, ZoneId.of("UTC")))
+    Optional<TimeBasedValue<IntValue>> actual = individualIntTimeSeries.getPreviousTimeBasedValue(ZonedDateTime.of(1990, 1, 1, 0, 5, 0, 0, ZoneId.of("UTC")))
 
     then:
     expected.present
@@ -103,7 +103,7 @@ class IndividualTimeSeriesTest extends Specification implements TimeSeriesTestDa
     Optional<TimeBasedValue<IntValue>> expected =  Optional.of(new TimeBasedValue<>(ZonedDateTime.of(1990, 1, 1, 0, 15, 0, 0, ZoneId.of("UTC")), new IntValue(4)))
 
     when:
-    Optional<TimeBasedValue<IntValue>> actual = individualIntTimeSeries.getNextTimeBasedValue(ZonedDateTime.of(1990, 1, 1, 0, 15, 0, 0, ZoneId.of("UTC")))
+    Optional<TimeBasedValue<IntValue>> actual = individualIntTimeSeries.getNextTimeBasedValue(ZonedDateTime.of(1990, 1, 1, 0, 10, 0, 0, ZoneId.of("UTC")))
 
     then:
     expected.present
diff --git a/src/test/groovy/edu/ie3/test/common/TimeSeriesSourceTestData.groovy b/src/test/groovy/edu/ie3/test/common/TimeSeriesSourceTestData.groovy
index f99a6fdd1..9df990efb 100644
--- a/src/test/groovy/edu/ie3/test/common/TimeSeriesSourceTestData.groovy
+++ b/src/test/groovy/edu/ie3/test/common/TimeSeriesSourceTestData.groovy
@@ -20,6 +20,7 @@ final class  TimeSeriesSourceTestData {
 
   public static final ZonedDateTime TIME_00MIN = ZonedDateTime.parse("2020-01-01T00:00:00Z")
   public static final ZonedDateTime TIME_15MIN = ZonedDateTime.parse("2020-01-01T00:15:00Z")
+  public static final ZonedDateTime TIME_30MIN = ZonedDateTime.parse("2020-01-01T00:30:00Z")
 
   public static final PValue P_VALUE_00MIN = new PValue(
   Quantities.getQuantity(1000.0d, StandardUnits.ACTIVE_POWER_IN)