A month to have four Tuesdays or five?

Kelly wondered in a post featuring “Manuel de Falla’s wonderfully sensual, exotic, and fiery ballet El amor brujo.” Come to think of it, I’m not sure if it’s more frequent for a month to have four Tuesdays or five…

Because he asked: Every year generally has FOUR months out of twelve with five Tuesdays, and I surmise, any other day of the week. In the case of Tuesdays, the only exceptions are years beginning on a Tuesday, or leap years starting on a Monday, which will have FIVE months with five Tuesdays.

That was pretty easy to calculate on the World Almanac perpetual calendar. 

• All months have at least four Tuesdays. This is because a month has between 28 and 31 days, and 28 divided by 7 (the number of days in a week) is 4. [Well, duh]
• Months with 5 Tuesdays are less common. For a month to have five Tuesdays, it needs to have 31 days and start on a Tuesday. Alternatively, a month with 30 days can have five Tuesdays if it starts on a Tuesday.
• In 2022, only two months had five Tuesdays: April and July.
• The remaining 10 months of 2022 had four Tuesdays. 

Is AI imperfect?

NO, NO, NO! And on several counts. 2022 did not have April and July start on a Tuesday; 2025 does! Okay, it was a “typo.” 

However, a month can also have five Tuesdays if it begins on a Sunday with 31 days, on a Monday with 30 or 31 days, or on a Tuesday with 29 days.

This digital response upset me, frankly, because I can imagine someone Googling an answer and accepting the results without thinking.

Here are the non-leap year possible calendars:

January 1 is a Sunday. The five-Tuesday months are January (which, of course, begins on Sunday), May (which begins on Monday), August (which begins on Tuesday), and October (which begins on Sunday). 2006, 2017, 2023, 2034

January 1 is a Monday. The five-Tuesday months are January (Monday), May (Tuesday), July (Sunday), and October (Monday). 2001, 2007, 2018, 2029

January 1 is a Tuesday. The five-Tuesday months are January (Tuesday), April (Monday), July (Monday), October (Tuesday), and December (Sunday). 2002, 2013, 2019, 2030

January 1 is a Wednesday. The five-Tuesday months are April (Tuesday), July (Tuesday), September (Monday), and December (Monday). 2003, 2014, 2025, 2031

January 1 is a Thursday. The five-Tuesday months are March (Sunday), June (Monday), September (Tues), and November (Sunday). 2009, 2015, 2026

January 1 is a Friday. The five-Tuesday months are March (Monday), June (Tuesday), August (Sunday), and November (Monday). 2010, 2021, 2027

January 1 is a Saturday. The five-Tuesday months are March (Tuesday), May (Sunday), August (Monday), and November (Tuesday). 2005, 2011, 2022, 2033

You can figure out the leap years yourselves. I will note that the five-Tuesday February was last in 2000 and will happen again in 2028.  

The Rolling Stones – Ruby Tuesday

The Moody Blues – Tuesday Afternoon