The date can only be set for today or some day in the future (in other words this is fine). However, reminders do not require either a title or description (although neither being missing cause any issues on the schedule page).
In addition, the time can be set to a time which has already past (e.g., setting the reminder for 12 AM) which does not cause any issues on the schedule page. However, the Up Next card on the dashboard displays the incorrect amount of time until the event (it seems displays the minutes part of the current time).
The date can only be set for today or some day in the future (in other words this is fine). However, reminders do not require either a title or description (although neither being missing cause any issues on the schedule page). In addition, the time can be set to a time which has already past (e.g., setting the reminder for 12 AM) which does not cause any issues on the schedule page. However, the Up Next card on the dashboard displays the incorrect amount of time until the event (it seems displays the minutes part of the current time).