Add your league match to the match calendar.
Your opponent's username
Date and Time
If all fields are filled you may add to the calendar directly by clicking "Add to Calendar." Clicking "More Options" will bring you to a longer form pre-filled with the information above where you will have options such as using a different time zone, requesting commentary, and leaving additional comments.
The above buttons may not work on some iOS devices. This is being worked on. If you are having trouble with them, please go to the general calendar form here.