a surprisingly good slack feature is that it shows you the local time of whoever you're chatting with... seems like this would be a nice little (opt-in) thing for discord
related and in addition, discord already allows you to send unix timecodes that automatically comvert to date/time in the user's timezone (type <t:0000000000> displays (for GMT users) January 1, 1970 12:00AM) and i think a convenient way to just send times or dates without having to go find unix times yourself would be really really useful