moment/moment — pull request #1311 by ericstob (2013-11-26 18:57:43+00:00)
Title: Add quarter 'q' to format string

I added a 'q' to the format string that will output the quarter.
January - March will output 1.
April - June will output 2.
July - September will output 3.
October - December will output 4.
I added a test in format.js called "quarter formats"