Google Now keeps getting smarter. As reported by Android Police, Google has started offering to add events to your Calender by way of Google Now based on your Gmail conversations.
Google Now can already remind you about flights or appointments from official emails. This new feature, however, will recognise natural language conversations. So, for example, if you send an email with “Hey John, do you want to meet up this Saturday at 2pm?” Google could recognise this as a potential event and offer to add it to your calendar. This, in turn, will result in Google Now cards when that event gets close.
Google Steps Up Gmail And Calendar Integration In Google Now With Inferred Events [Android Police]