finance dates

Fast date ranges, holiday calendars, and trading hours for financial markets

Overview

finance-dates provides calendar-aware date utilities for the finance-* stack. The Rust core handles holiday-rule expansion, weekend observance, early closes, and DST-aware regular and extended trading sessions; the Python package exposes a compact API for date series, exchange calendars, and open/close timestamps.

The library is useful when you need to answer questions like:

What are the valid trading dates for NYSE between two dates?
Which dates in a range are holidays or otherwise invalid for a venue?
Is a UTC timestamp inside a market session after DST and early closes?
What are the UTC open/close datetimes for regular and extended trading windows?

Quick start

from datetime import date, datetime, timezone

from finance_dates import Calendar
from finance_enums import EnergyType, ExchangeCode, UnderlyingAssetClass

c = Calendar.from_range(start=date(2024, 1, 1), end=date(2024, 1, 5))

# Inclusive plain calendar dates.
c.days()

# Mon-Fri only, holiday-blind.
c.business_days()

# Exchange-aware calendar with holidays, sessions, and early closes.
nyse = Calendar.from_exchange("XNYS")
nyse.business_days(date(2024, 7, 1), date(2024, 7, 5))
nyse.holidays(date(2024, 7, 1), date(2024, 9, 30))
nyse.sessions(date(2024, 7, 1), date(2024, 7, 5))
nyse.extended_sessions(date(2024, 7, 1), date(2024, 7, 5))
nyse.is_open(datetime(2024, 3, 11, 13, 30, tzinfo=timezone.utc))

gas = Calendar.from_asset(
  ExchangeCode.XNYM,
  UnderlyingAssetClass.Commodity,
  subclass=EnergyType.NaturalGas,
)
gas.regular_sessions

For US equity calendars, regular_sessions contains the standard 09:30-16:00 New York session template, while extended_hours includes pre_open and after_close templates. On early-close days, the after-close window begins at the early close.

Calendars with lunch breaks expose multiple regular session templates. For example, Tokyo (XTKS) currently returns separate 09:00-11:30 and 12:30-15:30 local sessions, and sessions() returns one UTC open/close pair per regular interval. Tokyo is date-effective around the 2024-11-05 close-time extension, so historical dates before that change close at 15:00 local while current dates close at 15:30.

Commodity futures can also use split sessions. Prefer Calendar.from_asset() with finance-enums exchange and asset/subclass enum members, or their string values, when you know the instrument vocabulary; for example ExchangeCode.XNYM plus EnergyType.NaturalGas resolves to the NYMEX energy template without requiring synthetic names like NYMEX_ENERGY. Synthetic product-group codes such as CBOT_GRAINS and product mnemonics such as CL or ZC remain accepted by from_exchange() for lower-level calendar inspection and compatibility.

Exchange and country calendars

Calendars can be resolved by exchange/MIC code or by ISO country code:

from finance_dates import Calendar
from finance_enums import EnergyType, ExchangeCode, UnderlyingAssetClass

Calendar.from_exchange("XLON")   # London Stock Exchange
Calendar.from_exchange("XTKS")   # Tokyo Stock Exchange, split lunch sessions
Calendar.from_exchange("XCME")   # CME futures-style overnight sessions
Calendar.from_exchange("CBOT_GRAINS")  # CBOT grain/oilseed futures sessions
Calendar.from_exchange("CME_ENERGY")  # Globex energy-category alias
Calendar.from_asset(ExchangeCode.XNYM, UnderlyingAssetClass.Commodity, subclass=EnergyType.NaturalGas)
Calendar.from_product("ICE_US", "Sugar")  # ICE US product-specific template
Calendar.from_exchange("FOREX")  # 24x5 FX family
Calendar.from_region("US")       # representative US equity calendar

Calendar.from_exchange() accepts additional resolver-only calendar aliases such as CBOT_GRAINS, CME_ENERGY, CL, and ZC; those are documented in the Calendars page.

Documentation

See the Calendars page for supported concepts, market families, date-series patterns, and trading-hours conventions. See the API page for the public Python API and recipes.

Rust crate

The Rust library crate is published as finance-dates and imported as finance_dates in Rust code:

[dependencies]
finance-dates = "0.1.0"

use finance_dates::{calendar_for_exchange, date_range};