@burglekitt/gmt/dist/plain/parse/parseDayOfWeekFromDate.js

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

import { Temporal } from "@js-temporal/polyfill";
import { isValidDate } from "../validate/index.js";
/**
 * Return the day of week (1-7) for a given ISO 8601 date string.
 *
 * - Monday=1 through Sunday=7.
 * - Returns null for invalid input.
 *
 * @param value ISO date string
 * @returns Day of week (1-7) or null on invalid input
 *
 * @example parseDayOfWeekFromDate("2024-01-01") // 1 (Monday)
 * @example parseDayOfWeekFromDate("2024-01-07") // 7 (Sunday)
 * @example parseDayOfWeekFromDate("2024-01-08") // 1 (Monday)
 * @example parseDayOfWeekFromDate("invalid") // null
 */
export function parseDayOfWeekFromDate(value) {
    if (!isValidDate(value)) {
        return null;
    }
    try {
        const date = Temporal.PlainDate.from(value);
        return date.dayOfWeek;
    }
    catch {
        return null;
    }
}