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JPY — Japan (Bank of Japan) Holidays

  • Standard: ISO 4217 JPY
  • Category: Central Bank/Settlement
  • Sibling calendars: JP (national) — JPY shares every JP holiday and both the cascade (振替休日) and sandwiched-day (国民の休日) rules verbatim, adding 3 BOJ-specific operational closures on top.
  • Service class: HolidayCalendarServiceJPY (org.holiday.calendar.impl, module org.holiday.calendar.apac), wrapped by the same package-private JapaneseHolidayCalendar used by JP

Weekend & Date Roll

  • Weekend days: Saturday+Sunday
  • Roll strategy: DateRolls.sundayToMonday() — identical to JP, including the cascading substitute-holiday and sandwiched-day logic layered on top by JapaneseHolidayCalendar (see JP.md for the full mechanism)
  • Rollability exceptions: identical to JP for the shared holidays. The 3 BOJ-specific closures (Year-Start Holiday ×2, Year-End Holiday) are rollable(false) and are not subject to the cascade rule — see Notes of Interest.

Holidays

Shares all 18 of JP's holidays (including both 2019 imperial-transition entries) verbatim — see JP.md for the full table. In addition:

Name Type First Year Rollable Notes
Year-Start Holiday FIXED — No January 2; BOJ operational closure
Year-Start Holiday FIXED — No January 3; BOJ operational closure
Year-End Holiday FIXED — No December 31; BOJ operational closure

Early Closes

Not applicable — JPY carries no EARLY_CLOSE entries; the three BOJ closures above are modeled as full FIXED holidays, not half-days.

Notes of Interest

The BOJ-specific closures were themselves the subject of a closed bug (#133): "cascade logic incorrectly bypasses BOJ Year-Start Holiday when rolling New Year's Day." Because JPY reuses the same JapaneseHolidayCalendar cascade/sandwich wrapper as JP, and because January 2/3 sit immediately adjacent to New Year's Day, there was a real risk of the cascade mechanism (see JP.md) mis-handling the interaction between New Year's Day rolling off a Sunday and the fixed, non-rollable Jan 2/3 closures already occupying those dates. This is now fixed, but is a good illustration of why layering BOJ-specific closures onto an already-complex cascade/sandwich calendar is riskier than it looks — a naive "just add three more FIXED holidays" implementation could plausibly reintroduce this exact class of bug.

JPY is the only calendar in this codebase's APAC module with genuine bank-specific closures layered on top of a national calendar that itself has non-trivial computed logic (cascade + sandwich), rather than a simple superset of Gregorian dates. Every other sibling pair in this codebase (Singapore's SG/SGD/XSES, China's CN/CNY) adds its market- or bank-specific content to a comparatively simpler base list.

Sources

  • See JP.md — JPY inherits the same underlying facts, sources, and closed-issue history for the cascade/sandwich mechanism
  • The BOJ Jan 2/Jan 3/Dec 31 closures and the #133 cascade-interaction history are documented directly in this project's own source comments (HolidayCalendarServiceJPY.java); no official Bank of Japan primary-source page was independently captured with a stable citation URL in this pass