Exactly 14% of all September 13ths are Mondays in the Gregorian calendar.
Monday on the Gregorian calendar; Thursday on the Julian calendar
Monday on the Gregorian calendar Thursday on the Julian calendar
Monday on the Gregorian calendar Thursday on the Julian calendar
Tuesday on the Gregorian calendar Monday on the Julian calendar
That's a Monday on the Julian calendar and a Tuesday on the proleptic Gregorian calendar.
That's a Wednesday on the Julian calendar and a Monday on the proleptic Gregorian calendar.
Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.Monday is the second day of the week in a Gregorian calendar.
January 1, 1 is a Monday on the Gregorian calendar, and it is a Saturday on the Julian calendar.
August 1 is a Monday in 14.5% of all years of the Gregorian calendar. The next occurrence will be in 2016.
April 16, 1072 is a Monday on the Julian calendar.(On the proleptic Gregorian calendar it's a Tuesday.)
The Gregorian calendar repeats every 400 years. In 56 years of every 400-year period, the 25th of October falls on a Monday. That's an average of 14 years per century.
The 8th of April of 1066 was a Monday. On the proleptic Gregorian calendar it's a Sunday.