diff --git a/lib/gpx/point.rb b/lib/gpx/point.rb
index 8aa0565..e697bf5 100644
--- a/lib/gpx/point.rb
+++ b/lib/gpx/point.rb
@@ -90,9 +90,11 @@ module GPX
          pt = Element.new('trkpt')
          pt.attributes['lat'] = lat
          pt.attributes['lon'] = lon
-         time_elem = Element.new('time')
-         time_elem.text = time.xmlschema
-         pt.elements << time_elem
+         unless time.nil?
+            time_elem = Element.new('time')
+            time_elem.text = time.xmlschema
+            pt.elements << time_elem
+         end
          elev = Element.new('ele')
          elev.text = elevation
          pt.elements << elev
diff --git a/lib/gpx/segment.rb b/lib/gpx/segment.rb
index 43dbc45..ed83056 100644
--- a/lib/gpx/segment.rb
+++ b/lib/gpx/segment.rb
@@ -204,8 +204,10 @@ module GPX
       end
 
       def update_meta_data(pt, last_pt)
-         @earliest_point = pt if(@earliest_point.nil? or pt.time < @earliest_point.time)
-         @latest_point   = pt if(@latest_point.nil? or pt.time > @latest_point.time)
+         unless pt.time.nil?
+            @earliest_point = pt if(@earliest_point.nil? or pt.time < @earliest_point.time)
+            @latest_point   = pt if(@latest_point.nil? or pt.time > @latest_point.time)
+         end
          unless pt.elevation.nil?
             @lowest_point   = pt if(@lowest_point.nil? or pt.elevation < @lowest_point.elevation)
             @highest_point  = pt if(@highest_point.nil? or pt.elevation > @highest_point.elevation)