Perfect month
A perfect month or a rectangular month designates a month whose number of days is divisible by the number of days in a week and whose first day corresponds to the first day of the week.[1][2] This causes arrangement of days of the month to resemble a rectangle. In the Gregorian calendar, this arrangement can only occur for the month of February.
Constraints[edit]
To satisfy such an arrangement in the Gregorian calendar, the number of days in the month must be divisible by seven. Only the month of February of a common year can meet this constraint as the month has 28 days, a multiple of 7.[3]
In order for a February to be a perfect month, the month must start on the first day of the week (usually considered to be Sunday or Monday). For Sunday-first calendars, this means that the year must start on a Thursday. As for Monday-first calendars, the year must start on a Friday. It must also occur in a common year, as the phenomenon does not occur when February has 29 days.
Occurrence[edit]
In the Gregorian calendar, the phenomenon occurs every six years or eleven years following a 6-11-11 sequence until the end of the 21st century. The most recent perfect months were February 2015 (Sunday-first) and February 2021 (Monday-first).[4] Due to calculation rules, the years 1800 and 1900 are not leap years, causing a shift in the sequence with a spacing of twelve years between 1790 and 1802 and between 1897 and 1909 respectively; however 2094, 2100 and 2106 will all feature perfect months with spacings of six years on Monday-first calendars.
The next perfect months will be February 2026 (Sunday-first) and February 2027 (Monday-first).
Attributes[edit]
The calendar arrangement brings together notions of harmony and organization.[5][6]
References[edit]
- ^ Norris, Phil (2021-02-01). "February is looking to be a perfect month on paper". GloucestershireLive. Retrieved 2021-02-01.
- ^ de La Taille, François (2021-01-31). ""Mois parfait", palindrome: quand février 2021 rend fous les fétichistes des chiffres". bfmtv.com (in French). Retrieved 2021-02-01.
- ^ Shaloo Tiwari (2021-02-01). "Why Is February 2021, a Rectangle Month? Happy Posts Take Over Twitter as the Second Month This Year Forms a Perfect Rectangle Shape!". latestly.com. Retrieved 2021-02-01.
- ^ Lombart, Gaël (2021-01-30). "Février 2021, mois «parfait»... sur le calendrier". leparisien.fr (in French). Retrieved 2021-02-01.
- ^ Focraud, Arnaud (2021-01-29). "En février, vous entrerez dans un "mois parfait" (selon le calendrier)". lejdd.fr (in French). Retrieved 2021-02-01.
- ^ Leray, Olivia (2021-02-01). "On ne pouvait pas le rater. Malgré le coronavirus, février sera parfait". francetvinfo.fr (in French). Retrieved 2021-02-01.