@burglekitt/gmt/dist/plain/get/getDayOfWeek.js

Temporal-based date and time utilities with timezone support and polyfill integration

import { Temporal } from "@js-temporal/polyfill";
import { getSystemTimeZone } from "../../zoned/get/getSystemTimeZone.js";
/**
 * Return the current ISO day of the week as a number in the system timeZone.
 *
 * - Uses Temporal.Now.zonedDateTimeISO to get current day in system timezone.
 * - Returns ISO day of week: 1 (Monday) to 7 (Sunday).
 * - Returns null when system timezone is unavailable.
 *
 * @returns current ISO day of week number (1-7) or null on invalid
 *
 * @example getDayOfWeek() // 4
 * @example getDayOfWeek() // null (when system timeZone unavailable)
 */
export function getDayOfWeek() {
    const timeZone = getSystemTimeZone();
    if (!timeZone)
        return null;
    try {
        const now = Temporal.Now.zonedDateTimeISO(timeZone);
        return now.dayOfWeek;
    }
    catch {
        return null;
    }
}