Dialogflow has the notion of a standard timezone per project, used eg to provide the real date for a utterance like "today" in system entities. However as users might not all be in the same timezone, I need to set the timezone per user/per conversation (users might travel across timezones). A timezone parameter is available in the dialogflow api when calling dialogflow from outside. However with the dialogflow actions-for-google/google assistant integration this api is only internally called.
Does anybody have a solution how to provide the timezone per conversation to dialogflow? Or are there any source code examples for a manual integration between actions-for-google and dialogflow (there is none at https://github.com/dialogflow/dialogflow-nodejs-client/tree/master/samples ...)?