isZonedBusinessDay

Signature

isZonedBusinessDay(value: string): boolean

import { isZonedBusinessDay } from "@northguild/gmt/zoned/compare";

Return true when value falls on a Monday–Friday ISO business day in the given timezone.

• Uses the fixed ISO Monday–Friday business-day boundary (Mon=1 … Fri=5), matching the definition used by addZonedBusinessDays/subtractZonedBusinessDays.
• Locale-agnostic: no Intl.Locale lookup and no holiday calendar.
• Returns false if value is invalid. This is the timezone-aware complement to the plain isBusinessDay: both use ISO Mon–Fri, but isZonedBusinessDay resolves the local day in the given timezone (so a UTC instant that is Friday evening may be Saturday morning in Asia/Tokyo and thus not a business day there).

Parameters

Parameter	Type	Description
value	string	ISO 8601 zoned datetime string

Returns

true if value is a Monday–Friday business day, false on invalid input

Examples

isZonedBusinessDay("2024-02-05T10:00:00-05:00[America/New_York]") // true (Monday)
isZonedBusinessDay("2024-02-10T10:00:00-05:00[America/New_York]") // false (Saturday)
isZonedBusinessDay("2024-02-04T10:00:00-05:00[America/New_York]") // false (Sunday)
isZonedBusinessDay("invalid") // false

Source

zoned/compare/isZonedBusinessDay.ts