Reminders can be used by
@everyone 
Adding reminders
Use/reminders create what: when: to create reminder.
Example usage
Managing reminders
Use/reminders list to view your reminders and the reminder_id
Use /reminders delete reminder_id: followed by the reminder id to delete the reminder
Reminder in DMs
Once you get a reminder in your DMs you can mark it as completed or set a duration to be reminded of it again in the future.