I was working on a cross country training plan and realized that somebody else may be interested in the single letter abbreviations I use for the names of weekdays. Here they are:

M – Monday
U – Tuesday
W – Wednesday
H – Thursday
F – Friday
R – Saturday
N – Sunday

The letter chosen for each day is the most unique letter letter from that name among all the letters used. M, W and F are perfectly unique because they only appear in those days, U appears four times, but is overshadowed in every name but Tuesday, H is also perfectly unique (my bad) and R and N are somehow the easiest of all of these to remember. Hope that helps, somehow.