title: Is there a single character day of the week convention?
body: <p>Is there a single character convention for the days of the week in English (or programmer-specific) and if so what is it?  I realize this could be an English language question but I think it has special significance for programmers.</p>
  
  <p>Maybe something like:</p>
  
  <pre><code>Monday    Mon  MO  M
  Tuesday   Tue  TU  T
  Wednesday Wed  WE  W
  Thursday  Thu  TH  U
  Friday    Fri  FR  F
  Saturday  Sat  SA  S
  Sunday    Sun  SU  N
  </code></pre>