[Feature Request] Event calendar for servers

With Discord moving on to embrace a larger variety of audiences. It will be nice to implement an event calendar for servers. School server can mark test date/submission date on the calendar, gaming server can mark the Streaming date, product server can mark release date.

Just like the text channel, there be a special channel at the top named calender. When people click it, a calendar will appear in the chat area. If you subscribed to the calendar you will automatically receive notification from it. Admins can add and remove events.

There will be a lot of possibilities for this feature for different groups.