diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 8363df9098..f605d07482 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -16,6 +16,7 @@
 			<action dev="joniles" type="update">Improve recognition of non-working days when reading calendars certain PMXML files.</action>
 			<action dev="joniles" type="update">Add support for the Resource Assignment field Remaining Units. (Note: this field defaults to the same value as Units if it is not explicitly populated).</action>
 			<action dev="joniles" type="update">Ensure the Resource Assignment field Remaining Units is read from and written to P6 schedules.</action>
+			<action dev="joniles" type="update">Improve handling of invalid calendar exception data when reading P6 schedules from XER files or a P6 database.</action>
 		</release>
 		<release date="2024-07-08" version="13.0.2">
 			<action dev="joniles" type="update">When writing XER files, provide a default value for the Resource ID if it is not populated.</action>
diff --git a/src/main/java/net/sf/mpxj/primavera/PrimaveraReader.java b/src/main/java/net/sf/mpxj/primavera/PrimaveraReader.java
index d53a390caa..51423ab90e 100644
--- a/src/main/java/net/sf/mpxj/primavera/PrimaveraReader.java
+++ b/src/main/java/net/sf/mpxj/primavera/PrimaveraReader.java
@@ -655,7 +655,26 @@ private void processCalendarExceptions(ProjectCalendar calendar, StructuredTextR
    {
       for (StructuredTextRecord exception : exceptions.getChildren())
       {
-         long daysFromEpoch = Integer.parseInt(exception.getAttribute("d"));
+         long daysFromEpoch;
+
+         try
+         {
+            daysFromEpoch = Integer.parseInt(exception.getAttribute("d"));
+         }
+
+         catch (NumberFormatException ex)
+         {
+            if (m_ignoreErrors)
+            {
+               m_project.addIgnoredError(ex);
+               continue;
+            }
+            else
+            {
+               throw ex;
+            }
+         }
+
          LocalDate startEx = EXCEPTION_EPOCH.plusDays(daysFromEpoch);
 
          ProjectCalendarException pce = calendar.addCalendarException(startEx, startEx);