diff --git a/onebusaway-gtfs-transformer/src/main/java/org/onebusaway/gtfs_transformer/factory/TransformFactory.java b/onebusaway-gtfs-transformer/src/main/java/org/onebusaway/gtfs_transformer/factory/TransformFactory.java
index 8385ee2d0..c2c56e22f 100644
--- a/onebusaway-gtfs-transformer/src/main/java/org/onebusaway/gtfs_transformer/factory/TransformFactory.java
+++ b/onebusaway-gtfs-transformer/src/main/java/org/onebusaway/gtfs_transformer/factory/TransformFactory.java
@@ -246,6 +246,9 @@ else if (opType.equals("update_trips_for_sdon")) {
         else if (opType.equals("last_stop_to_headsign")){
           handleTransformOperation(line, json, new LastStopToHeadsignStrategy());
         }
+        else if (opType.equals("truncate_calendars")){
+          handleTransformOperation(line, json, new CalendarTruncationStrategy());
+        }
         else if (opType.equals("transform")) {
           handleTransformOperation(line, json);
         } else {
diff --git a/onebusaway-gtfs-transformer/src/main/java/org/onebusaway/gtfs_transformer/updates/CalendarTruncationStrategy.java b/onebusaway-gtfs-transformer/src/main/java/org/onebusaway/gtfs_transformer/updates/CalendarTruncationStrategy.java
new file mode 100644
index 000000000..2766b6f2e
--- /dev/null
+++ b/onebusaway-gtfs-transformer/src/main/java/org/onebusaway/gtfs_transformer/updates/CalendarTruncationStrategy.java
@@ -0,0 +1,60 @@
+/**
+ * Copyright (C) 2018 Metropolitan Transportation Authority
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onebusaway.gtfs_transformer.updates;
+
+import org.onebusaway.csv_entities.schema.annotations.CsvField;
+import org.onebusaway.gtfs.model.ServiceCalendar;
+import org.onebusaway.gtfs.model.ServiceCalendarDate;
+import org.onebusaway.gtfs.model.calendar.ServiceDate;
+import org.onebusaway.gtfs.serialization.mappings.ServiceDateFieldMappingFactory;
+import org.onebusaway.gtfs.services.GtfsMutableRelationalDao;
+import org.onebusaway.gtfs_transformer.services.GtfsTransformStrategy;
+import org.onebusaway.gtfs_transformer.services.TransformContext;
+
+import java.util.ArrayList;
+
+public class CalendarTruncationStrategy implements GtfsTransformStrategy {
+
+    @CsvField(mapping = ServiceDateFieldMappingFactory.class)
+    private ServiceDate calendarEndDate;
+
+    @Override
+    public String getName() {
+        return this.getClass().getSimpleName();
+    }
+
+    @Override
+    public void run(TransformContext context, GtfsMutableRelationalDao dao) {
+        for (ServiceCalendar sc : dao.getAllCalendars()) {
+            if (sc.getEndDate().compareTo(calendarEndDate) > 0) {
+                sc.setEndDate(calendarEndDate);
+                dao.updateEntity(sc);
+            }
+        }
+
+        for (ServiceCalendarDate scd : new ArrayList<>(dao.getAllCalendarDates())) {
+            if (scd.getDate().compareTo(calendarEndDate) > 0) {
+                dao.removeEntity(scd);
+            }
+        }
+    }
+
+    public void setCalendarEndDate(ServiceDate calendarEndDate) {
+        this.calendarEndDate = calendarEndDate;
+    }
+
+}