diff --git a/tuhi.py b/tuhi.py
index 7eb8c05..811ee91 100755
--- a/tuhi.py
+++ b/tuhi.py
@@ -48,10 +48,10 @@ class TuhiDrawing(object):
                     d[key] = val
             return d
 
-    def __init__(self, name, dimensions):
+    def __init__(self, name, dimensions, timestamp):
         self.name = name
         self.dimensions = dimensions
-        self.timestamp = 0
+        self.timestamp = timestamp
         self.strokes = []
 
     def json(self):
@@ -61,6 +61,7 @@ class TuhiDrawing(object):
             'version': JSON_FILE_FORMAT_VERSION,
             'devicename': self.name,
             'dimensions': list(self.dimensions),
+            'timestamp': self.timestamp,
             'strokes': [s.to_dict() for s in self.strokes]
         }
         return json.dumps(json_data)
@@ -95,7 +96,7 @@ class TuhiDevice(GObject.Object):
 
     def _on_drawing_received(self, device, drawing):
         logger.debug('Drawing received')
-        d = TuhiDrawing(device.name, (0, 0))
+        d = TuhiDrawing(device.name, (0, 0), drawing.timestamp)
         for s in drawing:
             stroke = TuhiDrawing.Stroke()
             lastx, lasty, lastp = None, None, None
diff --git a/tuhi/wacom.py b/tuhi/wacom.py
index b9b1eed..511f21a 100644
--- a/tuhi/wacom.py
+++ b/tuhi/wacom.py
@@ -461,10 +461,15 @@ class WacomDevice(GObject.Object):
         return v, dv, is_rel
 
     def parse_pen_data(self, data, timestamp):
+        """
+        :param timestamp: a tuple with 9 entries, corresponding to the
+        local time
+        """
         offset = 0
         x, y, p = 0, 0, 0
         dx, dy, dp = 0, 0, 0
 
+        timestamp = int(time.mktime(timestamp))
         drawings = []
         drawing = None
         stroke = None