Architecture

Architecture

The library separates Gregorian arithmetic, date values, cell topology, and rendering-oriented masks. A month grid is a value: it contains at most 42 cells and associated metadata. No clock, time-zone database, process locale, network service, or heap collection participates in the core calculations.

CivilDate and YearMonth cover Gregorian years 1 through 9999. Calendar arithmetic is pure and deterministic. GridMode.natural uses the minimum whole week count; GridMode.fixedSixWeeks always has six rows.

StaticMonth exposes a CTFE-evaluated MonthGrid and related constants. Use it when the year, month, and week start are source-level constants. Use MonthGrid.build for user input or other runtime values; that avoids requiring template instantiation for each value.

The compact fingerprint encodes first weekday, day count, week start, row count, and mode. It identifies layout-equivalent months only. It is neither a cryptographic hash nor a unique identifier for a date or month.