diff --git a/Julian.cpp b/Julian.cpp
index cbb1086..a2bc81b 100644
--- a/Julian.cpp
+++ b/Julian.cpp
@@ -88,6 +88,22 @@ bool Julian::operator!=(const Julian &date) const {
     return date_ == date.date_ ? false : true;
 }
 
+bool Julian::operator>(const Julian &date) const {
+    return date_ > date.date_ ? true : false;
+}
+
+bool Julian::operator<(const Julian &date) const {
+    return date_ < date.date_ ? true : false;
+}
+
+bool Julian::operator>=(const Julian &date) const {
+    return date_ >= date.date_ ? true : false;
+}
+
+bool Julian::operator<=(const Julian &date) const {
+    return date_ <= date.date_ ? true : false;
+}
+
 /*
  * create julian date from year and day of year
  */
diff --git a/Julian.h b/Julian.h
index 0f341bd..90c4a09 100644
--- a/Julian.h
+++ b/Julian.h
@@ -13,8 +13,15 @@ public:
     Julian(int year, double day);
     Julian(int year, int mon, int day, int hour, int min, double sec);
 
+    /*
+     * comparison operators
+     */
     bool operator==(const Julian &date) const;
     bool operator!=(const Julian &date) const;
+    bool operator>(const Julian &date) const;
+    bool operator<(const Julian &date) const;
+    bool operator>=(const Julian &date) const;
+    bool operator<=(const Julian &date) const;
 
     ~Julian() {
     };