diff --git a/engine/time/src/test/java/io/deephaven/time/calendar/TestBusinessCalendarParser.java b/engine/time/src/test/java/io/deephaven/time/calendar/TestBusinessCalendarParser.java
index c6d81794706..285916d4bb8 100644
--- a/engine/time/src/test/java/io/deephaven/time/calendar/TestBusinessCalendarParser.java
+++ b/engine/time/src/test/java/io/deephaven/time/calendar/TestBusinessCalendarParser.java
@@ -13,13 +13,7 @@
 
 public class TestBusinessCalendarParser extends BaseArrayTestCase {
 
-    public void testLoad() throws URISyntaxException {
-        final String path = Paths
-                .get(Objects.requireNonNull(TestBusinessCalendarParser.class.getResource("/PARSER-TEST.calendar")).toURI())
-                .toString();
-        final File f = new File(path);
-        final BusinessCalendar cal = BusinessCalendarParser.loadBusinessCalendar(f);
-
+    public static void assertParserTestCal(final BusinessCalendar cal) {
         assertEquals("PARSER-TEST-CAL", cal.name());
         assertEquals("Test Calendar", cal.description());
         assertEquals(DateTimeUtils.timeZone("Asia/Tokyo"), cal.timeZone());
@@ -37,4 +31,13 @@ public void testLoad() throws URISyntaxException {
         assertEquals(DateTimeUtils.parseInstant("2015-04-06T14:15 Asia/Tokyo"), cal.businessSchedule("2015-04-06").businessStart());
         assertEquals(DateTimeUtils.parseInstant("2015-04-06T16:46 Asia/Tokyo"), cal.businessSchedule("2015-04-06").businessEnd());
     }
+
+    public void testLoad() throws URISyntaxException {
+        final String path = Paths
+                .get(Objects.requireNonNull(TestBusinessCalendarParser.class.getResource("/PARSER-TEST.calendar")).toURI())
+                .toString();
+        final File f = new File(path);
+        final BusinessCalendar cal = BusinessCalendarParser.loadBusinessCalendar(f);
+        assertParserTestCal(cal);
+    }
 }
diff --git a/engine/time/src/test/java/io/deephaven/time/calendar/TestCalendars.java b/engine/time/src/test/java/io/deephaven/time/calendar/TestCalendars.java
index 25a96b11ac3..28a39ec7314 100644
--- a/engine/time/src/test/java/io/deephaven/time/calendar/TestCalendars.java
+++ b/engine/time/src/test/java/io/deephaven/time/calendar/TestCalendars.java
@@ -6,6 +6,10 @@
 import io.deephaven.base.testing.BaseArrayTestCase;
 import io.deephaven.configuration.Configuration;
 
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+import java.util.Objects;
+
 public class TestCalendars extends BaseArrayTestCase {
 
     public void testDefault() {
@@ -39,4 +43,19 @@ public void testCalendar() {
             // pass
         }
     }
+
+    public void testAdd() throws URISyntaxException {
+
+        try{
+            final String path = Paths
+                    .get(Objects.requireNonNull(TestBusinessCalendarParser.class.getResource("/PARSER-TEST.calendar")).toURI())
+                    .toString();
+            Calendars.addCalendarFromFile(path);
+
+            final BusinessCalendar cal = Calendars.calendar("PARSER-TEST-CAL");
+            TestBusinessCalendarParser.assertParserTestCal(cal);
+        }finally {
+            Calendars.setDefaultCalendar(Configuration.getInstance().getProperty("Calendar.default"));
+        }
+    }
 }