10month

10month is a term used to refer to several distinct concepts, rather than a single standardized unit. In discussions of calendars and timekeeping, it is most often invoked as a hypothetical or proposed ten-month year.

In a ten-month calendar, the year would be divided into ten months instead of twelve. Month lengths could be fixed, such as ten months of 36 days, or variable, with a combination of 28–31 or 30–31-day months. Such systems have appeared in reform proposals and fictional worldbuilding, but none has achieved broad adoption. Implementing a ten-month year would require reworking leap-year rules, religious and public holidays, fiscal cycles, and international date standards, creating substantial coordination challenges.

As a unit of time, ten months is sometimes used informally to describe a period spanning roughly ten calendar months. It is not an official SI unit or universally recognized measure.

Outside of timekeeping, "10month" appears as a brand name, product title, or project identifier in branding and media contexts. In these uses, meaning is determined by the creators and is not tied to a universal definition.

In fiction and worldbuilding, ten-month calendars are used to craft alternative cultures with distinct seasonal patterns, festivals, and economic rhythms. They serve as a narrative device to explore how calendar structure shapes society.