diff --git a/birthdays.test b/birthdays.test
index b1d4430..73978bf 100644
--- a/birthdays.test
+++ b/birthdays.test
@@ -90,6 +90,15 @@ class BirthdaysBirthdayTestCase extends DrupalUnitTestCase {
       $this->pass($e->getMessage());
     }
   }
+
+  /**
+   * Tests BirthdaysBirthday::isLeapYear().
+   */
+  function testLeapYear() {
+    $this->assertTrue(BirthdaysBirthday::isLeapYear(2012));
+    $this->assertTrue(BirthdaysBirthday::isLeapYear(2000));
+    $this->assertFalse(BirthdaysBirthday::isLeapYear(2001));
+  }
 }
 
 /**
diff --git a/birthdays_birthday.inc b/birthdays_birthday.inc
index 075e840..77989d8 100644
--- a/birthdays_birthday.inc
+++ b/birthdays_birthday.inc
@@ -324,4 +324,17 @@ class BirthdaysBirthday {
         return $day < 22 ? 'sagittarius' : 'capricorn';
     }
   }
+
+  /**
+   * Checks if a given year is a leap year.
+   *
+   * @param $year
+   *   The year.
+   *
+   * @return
+   *   TRUE if it is a leap year.
+   */
+  public function isLeapYear($year) {
+    return (bool) date('L', strtotime($year . '-1-1'));
+  }
 }