diff --git a/src/main/java/net/fortuna/ical4j/model/TemporalAmountAdapter.java b/src/main/java/net/fortuna/ical4j/model/TemporalAmountAdapter.java
index 17fb0dc17..34356deff 100644
--- a/src/main/java/net/fortuna/ical4j/model/TemporalAmountAdapter.java
+++ b/src/main/java/net/fortuna/ical4j/model/TemporalAmountAdapter.java
@@ -131,7 +131,7 @@ public static TemporalAmountAdapter fromDateRange(Date start, Date end) {
         TemporalAmount duration;
         long durationMillis = end.getTime() - start.getTime();
         if (durationMillis % (24 * 60 * 60 * 1000) == 0) {
-            duration = java.time.Period.ofDays((int) durationMillis / (24 * 60 * 60 * 1000));
+            duration = java.time.Period.ofDays((int) (durationMillis / (24 * 60 * 60 * 1000)));
         } else {
             duration = java.time.Duration.ofMillis(durationMillis);
         }
diff --git a/src/test/groovy/net/fortuna/ical4j/model/TemporalAmountAdapterTest.groovy b/src/test/groovy/net/fortuna/ical4j/model/TemporalAmountAdapterTest.groovy
index 7aaa65813..eab5ab4bc 100644
--- a/src/test/groovy/net/fortuna/ical4j/model/TemporalAmountAdapterTest.groovy
+++ b/src/test/groovy/net/fortuna/ical4j/model/TemporalAmountAdapterTest.groovy
@@ -51,16 +51,25 @@ class TemporalAmountAdapterTest extends Specification {
         new Dur(-9)  | java.time.Period.ofWeeks(-9)
     }
 
+    def 'test creation from  date range'() {
+        expect:
+        TemporalAmountAdapter.fromDateRange(new DateTime(start), new DateTime(end)).duration == expectedTemporalAmount
+
+        where:
+        start   | end   | expectedTemporalAmount
+        '20200107T000000'   | '20200331T000000' | java.time.Period.ofWeeks(12)
+    }
+
     @Unroll
     def 'validate string representation: #dur'() {
         expect: 'derived string representation equals expected'
-        dur.toString() == expectedString
+        TemporalAmountAdapter.from(dur).toString() == expectedString
 
         where:
         dur						| expectedString
-        TemporalAmountAdapter.from(new Dur(33))				| 'P33W'
-        TemporalAmountAdapter.from(new Dur('-P2D'))			| '-P2D'
-        TemporalAmountAdapter.from(new Dur(-2, 0, 0, 0))	| '-P2D'
+        new Dur(33)				| 'P33W'
+        new Dur('-P2D')			| '-P2D'
+        new Dur(-2, 0, 0, 0)	| '-P2D'
     }
 
     @Unroll