Every time February 1st falls on a Monday !
Never.
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
October 2011, December 2012, March 2014 for starters. In other words, how often does a 31-day month begin on a Saturday? Fairly often.
more often tahn not
more often, most often
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.
March
ummm...never.
About twice each year
every 823 years.
Never.
once every 365 years!
This happens in any 31-day month starting on Friday (such as July 2005).
According to my desktop calendar, July will have five Fridays and Saturdays (and even some Thursdays) in 2016, 2021, 2022, 2027,2032, 2033, etc... If you look at http://www.timeanddate.com/calendar/monthly.html?year=2021&month=7&country=1 you will see that 2021, 2027, 2032 do not have 5 Sundays. The other years 2016, 2022, 2033 do have 5 Fridays, Saturdays, and Sundays. You are little confused since your first parahraph discusses Fridays and Saturdays, in which case 2021 and 2022 do indead have 5 Fridays and 5 Saturdays in July. In paragraph two above, you begin talking about Sundays and which years in which July will 5 each of Fridays, Saturdays and Sundays. Every month with 31 days will have 5 instances of the first 3 days in the month. This will repeat in a 5-6-5-11 year cycle and then repeat. So it should be 2016, 2022, 2033, 2039, 2044, 2050, 2056 - don't forget to consider leap year which will cause a 1 day shift.
There are 14 calendar variations (7 days of the week plus leap years). Some years October will have 5 Fridays, 5 Saturdays, and 5 Sundays. October 1999, 2010, 2021, and 2032 all have 5 Fridays, 5 Saturdays, and 5 Sundays. This looks like an 11 year gap, but October 1988 and 2043 do not have 5 weekends.
The month of July has 5 Saturdays and 5 Sundays zerotimes in 2012.