Match Day Meaning

Example: The day graduating medical-school students find out where they will serve as residents.
1999, Ellen Lerner Rothman, White Coat, 2000 Perennial edition, ISBN 0688175899, page 318 [1]:
  On match day, at exactly noon, we would each receive a white envelope with a single piece of paper listing the hospital and program where we would spend the next several years.
2002, Richard C. Karl, Across the Red Line, Temple, ISBN 159213193X, page 117 [2]:
  The fourth-year medical students are getting anxious. It's getting close to match day. In a few weeks they will find out where they're going to spend the next several years of training.
Used other than as an idiom: The day of a match.
2001, David Griffiths, The Weekend Warrior, Reedswain, ISBN 1890946656, page 115 [3]:
  For a player to perform, his body machinery must be continually fuelled, oiled and checked long before the first whistle. Match day strategies involving the consumption of large amounts of food deemed to have a beneficial content with regard to performance should therefore not be used as a substitute for a poor diet across the preceding days or weeks.