At the moment I get the timestamp field in the request object as an ISO 8601 string, when I use my Alexa device (,"timestamp":"2017-07-08T08:53:31Z") . According to documentation (https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/docs/custom-standard-request-types-reference#intentrequest) this is correct. But when I use the test page in the developer console I get an integer timestamp ( ,"timestamp":1499503873307,).
Can someone else confirm this? @Amazon: please fix.