aion-lithuanian-market-calendar

Lithuanian public holiday, bank and market calendar. Never needs updating.

Lietuviškai: README.lt.md

pip install aion-lithuanian-market-calendar

from aion_lithuanian_market_calendar import is_business_day, next_business_day, holiday_on

is_business_day()                       # is today a working day in Lithuania
is_business_day("2026-12-25")           # False
next_business_day("2026-12-24")         # date(2026, 12, 28)

holiday_on("2026-06-24")
# Holiday(date=2026-06-24, name_en="St John's Day, Midsummer", name_lt="Rasos ir Joninės")

Why this never needs updating

Every Lithuanian statutory non-working day is computable. Twelve are fixed dates. Two derive from Easter. Two are the first Sunday of a named month.

So this package calculates them rather than shipping a table of dates that goes stale every December. Install it once and it is correct for 2027, 2040, and any year after that, offline, with no network call and no maintenance.

That is a deliberate difference from calendars for markets whose holidays are announced annually and genuinely cannot be derived.

Easter uses the Gregorian (Western) computus. Lithuania is predominantly Catholic and observes Western Easter, not the Orthodox date. Getting this wrong misplaces two holidays every year.

The sixteen statutory holidays

No substitute days. Lithuania does not move a holiday that falls on a weekend to the following Monday. Assumption Day on Saturday 15 August 2026 is simply absorbed.

API

is_business_day(when=None)          # working day for banks and offices
is_public_holiday(when=None)        # statutory non-working day
is_weekend(when=None)

next_business_day(after=None)
previous_business_day(before=None)
business_days_between(start, end)   # half-open interval

holidays(year)                      # all sixteen, ordered
holiday_on(day)                     # Holiday or None
easter_sunday(year)

is_market_open(at=None, market="XVIL")   # Nasdaq Vilnius

Dates accept date, datetime, an ISO string, or None for today.

Scope

Covers the sixteen statutory non-working days (šventės).

Lithuania also has commemorative and flag days (atmintinos dienos), which are official but remain working days, so they do not change business-day arithmetic and are out of scope here.

Exchange session times are the one part of a market calendar that changes by announcement rather than by rule. is_market_open uses standard Nasdaq Vilnius continuous trading hours; confirm against the venue if you need intraday precision.

Verification

Easter is unit-tested against known dates for 2024, 2025, 2026, 2027, 2030 and 2035. Mother's Day and Father's Day are asserted to fall on a Sunday for every year from 2024 to 2040. The full 2026 date list is pinned in the test suite.

Holiday dates should be confirmed against the Lithuanian Labour Code for any use with legal or financial consequence. Corrections are welcome as issues.

Related

• aion-indian-market-calendar — the Indian sibling
• aion-indian-market-intelligence

MIT licensed. Built by AION Analytics (India), an independent India-based firm, not affiliated with Aion Analytics LLC (United States) or AION Labs (Israel).