translate how to get the timestamp for lighting (#9656)

Author: BlueDrink9

bindings/pydeck/examples/polygon_layer.py

@@ -57,7 +57,7 @@ def calculate_elevation(val):
 # Add sunlight shadow to the polygons
 sunlight = {
     "@@type": "_SunLight",
-    "timestamp": 1564696800000,  # Date.UTC(2019, 7, 1, 22),
+    "timestamp": 1564696800000,  # datetime.datetime(2019, 7, 1, 22, tzinfo=datetime.timezone.utc).timestamp() * 1000
     "color": [255, 255, 255],
     "intensity": 1.0,
     "_shadow": True,