diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index 388b30ba7a..71d0da59f8 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -8555,17 +8555,24 @@ time_to_datetime(VALUE self)
  * call-seq:
  *    d.to_time  ->  time
  *
- * Returns a Time object which denotes self.
+ * Returns a Time object which denotes self. If self is a julian date,
+ * convert it to a gregorian date before converting it to Time.
  */
 static VALUE
 date_to_time(VALUE self)
 {
-    get_d1(self);
+    get_d1a(self);
+
+    if (m_julian_p(adat)) {
+        VALUE tmp = d_lite_gregorian(self);
+        get_d1b(tmp);
+        adat = bdat;
+    }
 
     return f_local3(rb_cTime,
-		    m_real_year(dat),
-		    INT2FIX(m_mon(dat)),
-		    INT2FIX(m_mday(dat)));
+        m_real_year(adat),
+        INT2FIX(m_mon(adat)),
+        INT2FIX(m_mday(adat)));
 }
 
 /*
diff --git a/test/date/test_date_conv.rb b/test/date/test_date_conv.rb
index 5c295daba6..d41ff45d85 100644
--- a/test/date/test_date_conv.rb
+++ b/test/date/test_date_conv.rb
@@ -48,6 +48,24 @@ class TestDateConv < Test::Unit::TestCase
 		 [t.year, t.mon, t.mday, t.hour, t.min, t.sec, t.usec])
   end
 
+  def test_to_time_to_date_roundtrip__from_gregorian_date
+    d = Date.new(1582, 10, 15)
+    t = d.to_time
+    assert_equal([1582, 10, 15, 0, 0, 0, 0],
+		 [t.year, t.mon, t.mday, t.hour, t.min, t.sec, t.usec])
+    assert_equal(d, t.to_date)
+    assert_equal(d.jd, t.to_date.jd)
+  end
+
+  def test_to_time_to_date_roundtrip__from_julian_date
+    d = Date.new(1582, 10, 4)
+    t = d.to_time
+    assert_equal([1582, 10, 14, 0, 0, 0, 0],
+		 [t.year, t.mon, t.mday, t.hour, t.min, t.sec, t.usec])
+    assert_equal(d, t.to_date)
+    assert_equal(d.jd, t.to_date.jd)
+  end
+
   def test_to_time__from_datetime
     d = DateTime.new(2004, 9, 19, 1, 2, 3, 8.to_r/24) + 456789.to_r/86400000000
     t = d.to_time