javatimechrono

javatimechrono is a hypothetical Java library designed to provide a comprehensive, chrono-inspired time API for Java applications. It aims to unify and extend Java's standard java.time API with a consistent set of time points, durations, and calendar arithmetic that mirrors the semantics of the Chrono family found in other languages.

Core concepts include TimePoint (an instant with nanosecond precision), Duration (sub-second and longer durations with nanosecond precision), Period (calendar-based differences), LocalDate, LocalTime, LocalDateTime, ZonedDateTime, and Clock. The library emphasizes immutable value types, precise time arithmetic, and clear handling of time zones through a built-in zone database and rules for daylight saving transitions.

Interoperability and API design emphasis is placed on seamless integration with existing Java time types. It provides conversion helpers to and from the standard java.time types, allowing incremental adoption. The API favours fluent method chaining for adding and subtracting durations or periods, rounding to fixed units, and performing common temporal calculations. Implementations are aimed at zero-allocation pathways where feasible and thread-safety.

Features include ISO-8601 parsing and formatting, high-precision arithmetic, time-zone aware calculations, and support for leap-year and leap-second conventions aligned with ISO standards. Utilities cover common patterns such as start and end of day, business-day calculations, and truncation or rounding to specified units.

Usage is typically described as obtaining a current TimePoint, converting to the desired time zone, performing arithmetic with Periods or Durations, and formatting results as ISO-8601 strings. The library is presented as a design concept for projects seeking a chrono-style API in Java.

History and adoption notes that javatimechrono is not part of the official Java platform and has no formal standardization; it exists mainly as an experimental concept or proposal with a small ecosystem of trials. See also java.time and Chrono-inspired libraries.