[Feature Req] Dynamic timestamp input support

It is currently possible to send a dynamically formatted timestamp within a message which is helpful for quickly allowing the user to see the exact time and date. However, there is no user-based UI element to help you insert a timestamp unless you manually use the appropriate message format for the timestamps. This feature is more geared toward automated bots leveraging the discord API. But I think it would also be helpful to the end-users (non-bot) on the desktop and mobile clients if there was a much more user-friendly way to add timestamps inside the message input. 

Imagine you're trying to schedule a call with your friend who lives in a different time zone, and you send a message like: "Hey, can we talk tomorrow at 5?" You can work out time-zone differences and all, but that can get confusing and is error-prone. Wouldn't it be helpful if you could pick a time and date, and then a correctly generated timestamp format syntax is added to the text input that you can send, and your friend on the other end sees the relative time in their local time zone?

A simple date-picker could be added, ideally somewhere near the message text input that lets you pick a date and time, and then it appends the timestamp formatting syntax to the message in the text input box. The relative time formatting is the most suitable style in the context of a chat conversation where you normally describe the time in short words.

Have a look at the image below:
https://i.imgur.com/yme0aDG.png 

(1) The plus icon within the message input launches a dialog.

(2) So maybe within that dialog, a new entry could be added that opens a date picker that lets you pick a time and date.

(3). Then the timestamp formatted string could be appended to the message inside the input.. 

 What do you think?