If December starts on a Monday, Tuesday or Wednesday, it will have 5 Wednesdays. That would be about 4 or 5 out of every 10 years. So it happens quite regularly.
The number of Wednesdays in a month can vary, typically ranging from four to five. A month with 30 days will usually have four Wednesdays, while a month with 31 days can have either four or five, depending on which day of the week the month starts. February usually has four Wednesdays, except in leap years when it can have five.
Exactly 42.75% of all Januaries have five Wednesdays.
December of 2012 is a five week month.
Five Sundays: March, June, September & December Five Mondays: April, July, September & December Five Tuesdays: January, April, July, October & December Five Wednesdays: January, May, July & October Five Thursdays: January, May, August & October Five Fridays: March, May, August & November Five Saturdays: March, June, August & November
2040
December 2017 will have five occurances of Friday-Saturday-Sunday in the same month.
That can only happen in a 31 day month. So it only happens in January, March, May, July, August, October and December.
A 31 days month starting on a Friday.
Any month of the year can have either four or five of any day of the week. The only exception is February of a non-leap year, which always has four of every day of the week.A 31-day month that begins on a Wednesday, Thursday or Friday has five Fridays. A 31-day month that begins on a Sunday, Monday, Tuesday or Saturday has four Fridays.Examples:December, 2011: five Fridays (starts on a Thursday)December, 2012: four Fridays (starts on a Saturday)December, 2013: four Fridays (starts on a Sunday)December, 2014: four Fridays (starts on a Monday)December, 2015: four Fridays (starts on a Tuesday)December, 2016: five Fridays (starts on a Thursday)
About twice each year
It starts this month December 2008 I have no idea when so keep watching!
The odds are exactly 14.5%, which makes the average frequency once per 6.9 years.