diff --git a/lib/time.rb b/lib/time.rb
index 5179e9fee4..bb5d0aac38 100644
--- a/lib/time.rb
+++ b/lib/time.rb
@@ -134,8 +134,8 @@ class Time
     def zone_offset(zone, year=self.now.year)
       off = nil
       zone = zone.upcase
-      if /\A([+-])(\d\d):?(\d\d)\z/ =~ zone
-        off = ($1 == '-' ? -1 : 1) * ($2.to_i * 60 + $3.to_i) * 60
+      if /\A([+-])(\d\d)(:?)(\d\d)(?:\3(\d\d))?\z/ =~ zone
+        off = ($1 == '-' ? -1 : 1) * (($2.to_i * 60 + $4.to_i) * 60 + $5.to_i)
       elsif /\A[+-]\d\d\z/ =~ zone
         off = zone.to_i * 3600
       elsif ZoneOffset.include?(zone)
diff --git a/test/test_time.rb b/test/test_time.rb
index 398ab7279b..9d7c976abf 100644
--- a/test/test_time.rb
+++ b/test/test_time.rb
@@ -343,6 +343,13 @@ class TestTimeExtension < Test::Unit::TestCase # :nodoc:
                  Time.parse("2000-01-01T00:00:00+11:00", nil))
   end
 
+  def test_parse_offset_hour_minute_second
+    t = Time.at(-100000000000).utc
+    assert_equal(t, Time.parse("1200-02-15 BC 14:13:20-00"))
+    assert_equal(t, Time.parse("1200-02-15 BC 14:13:20-00:00"))
+    assert_equal(t, Time.parse("1200-02-15 BC 14:13:20-00:00:00"))
+  end
+
   def test_parse_leap_second
     t = Time.utc(1998,12,31,23,59,59)
     assert_equal(t, Time.parse("Thu Dec 31 23:59:59 UTC 1998"))