Never.
Every time February 1st falls on a Monday !
October had 5 Fridays and Saturdays and Sundays in the year 2010 and will have it again in 2021 than 2027, 2032, 2038 , all the months with 31 days in them have the same pattern 11 years than 6 years than 5 years than 6years than 11 than 6 than 5 than 6 doesn't matter where you start at 5 or 6 or 11 just do 4 in a row and it will add up to 28 years October has 5 Fridays, Saturdays and Sundays. 5 times starting in 2010 , 2021, 2027,2032 and 2038 December will have them in 2017,2023,2028,2034 and 2045 January is 2010, 2016,2021,2027 and 2038 march is 2013,2019,2024,2030,2041 may is 2015,2020,2026,2037 and 2043 and the last month with 31 days in it, July has them on 2011,2016,2022,2033,and2039
more often tahn not
more often, most often
there 5 sundays,mondays,saturdays in every 200 years
4 years
Never.
The month of July has 5 Saturdays and 5 Sundays zerotimes in 2012.
March
ummm...never.
About twice each year
every 823 years.
Over the very long average, once for every seven years. And it's "often".
The odds are exactly 14.5%, which makes the average frequency once per 6.9 years.
Exactly 14% of all Decembers have five of each of Fridays, Saturdays and Sundays.
Every year has more than 5 Fridays, 5 Saturdays and 5 Sundays.