export class DateUtils { private static readonly DAY_NAMES = [ "sunday", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday", ] as const; private static readonly DAY_MAP = Object.fromEntries( DateUtils.DAY_NAMES.map((day, index) => [index, day]) ); public static getDayName(date: Date | string): string { const dateObj = typeof date === "string" ? new Date(date) : date; const dayOfWeek = dateObj.getDay(); return this.DAY_MAP[dayOfWeek]; } public static isWorkingDay( date: Date | string, workDays: string[] ): boolean { const dayName = this.getDayName(date); return workDays.includes(dayName); } }