Talk:Perfect month

Constraints

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] 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, and 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

In the Gregorian calendar, the phenomenon occurs every six years or eleven years following a 6-11-11, 11-6-11, or an 11-11-6 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 1700, 1800, and 1900 are not leap years, causing a shift in the sequence with a spacing of twelve years. For example, in Sunday-first calendars, there are spacings between 1795 and 1807; however 2094, 2100 and 2106 will all feature perfect months with spacings of six years on Monday-first calendars.

Attributes

The calendar arrangement brings together notions of harmony and organization.^[5][6]

Perfect months

See also

• Palindrome#Dates
• Perfectionism (psychology)
• Perfectionism (philosophy)

References