Board Thread:General Discussion/@comment-5751180-20131015193720/@comment-5751180-20131015194653

Wikipedia: All other week-numbering years have 52 weeks.
 * years with the dominical letter ED, D, or DC;
 * all years starting on Thursday, and leap years starting on Wednesday;
 * all years ending on Thursday, and leap years ending on Friday;
 * years in which either 1 January or 31 December is a Thursday (in leap years), or in which both are Thursdays (in common years).