@burglekitt/gmt/dist/utc/parse/parseDayOfWeekFromUtc.js

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

import { Temporal } from "@js-temporal/polyfill";
import { isValidUtc } from "../validate/index.js";
/**
 * Return the day of week (1-7) from a UTC datetime string.
 *
 * - Monday=1 through Sunday=7.
 * - Returns null for invalid input.
 *
 * @param value ISO UTC datetime string (e.g., "2024-03-17T14:30:45Z")
 * @returns Day of week (1-7) or null on invalid input
 *
 * @example parseDayOfWeekFromUtc("2024-03-17T14:30:45Z") // 7
 * @example parseDayOfWeekFromUtc("2024-03-18T00:00:00Z") // 1
 * @example parseDayOfWeekFromUtc("invalid") // null
 */
export function parseDayOfWeekFromUtc(value) {
    if (!isValidUtc(value))
        return null;
    try {
        const instant = Temporal.Instant.from(value);
        const dateTime = instant.toZonedDateTimeISO("UTC");
        return dateTime.dayOfWeek;
    }
    catch {
        return null;
    }
}