LocalDateTimeofyear

LocalDateTimeofyear is a data structure used in some date-time APIs to represent a specific moment within a calendar year by using the year and the ordinal day of year (dayOfYear) as primary coordinates. Unlike systems that specify a date with month and day of month, LocalDateTimeofyear emphasizes the year-long position of a moment, combined with time-of-day components. The local qualifier indicates that it does not include time-zone information.

Core components typically include year, dayOfYear (ranging from 1 to 365 or 366 in leap years), hour, minute, second, and nanosecond. The format is compatible with ISO calendar logic, where dayOfYear maps to a concrete month and day when resolved against the calendar rules of the year. Validation enforces the valid range for dayOfYear given the year.

Construction and conversion: You can construct an instance by specifying year, dayOfYear, and the time components. You can also convert to a standard LocalDateTime by resolving dayOfYear into month and day for that year, then attaching the time-of-day. Conversely, you can create LocalDateTimeofyear from a LocalDateTime by computing its year and dayOfYear.

Use cases: It is useful in calculations driven by the ordinal day of the year, such as day-number based scheduling, environmental data aggregation, or when working with anniversaries and seasonal analyses tied to the year rather than a fixed month-day. It also simplifies iterating through all days of a given year.

Limitations: The abstraction assumes the ISO proleptic Gregorian calendar. It requires careful handling of leap years, and can complicate formatting, range queries, and interoperability with systems using month-day representations. Performance considerations arise when frequent resolution between representations is needed. As with LocalDateTime, there is no inherent time zone information.