The Nex Calendar was created by Donny and Justin Lai in 2020. Its name derives from Natural EXtension of the current calendar. Its special feature is an extra Sunday at the beginning of September, otherwise it keeps the months of a Gregorian leap year, where the leap day has been changed to 31 December and is always a Sunday, i.e. February always has 29 days and December usually has but 30. With its two special Sundays it breaks with the traditional week cycle and is strictly perennial. Every quarter runs from Monday through Sunday and is either 91 or 92 days; the second half of the year is always longer than the first.