My spouse always collected JD calendar's and I get them since he passed. The calendars for February 2015, 2014, 2013, 2011 all contained exactly four Sundays, four Mondays, four Tuesdays etc. Surely this happens every February that has 28 days.
Our 1950 calendar is the exact same as the current 2017 February, started on Wednesday and ended on a Tuesday.