Calculate business hours excluding weekends and holidays formatted to nearest 30 mins. Typescript || Javascript

businesshourscalculation.ts

let startDate = new Date('2022/12/25  8:00');

let endDate = new Date('2022/12/27  9:30');

function calculateBusinessDays(startDate, endDate) {
    var minutesWorked = 0;
    var holidays = ['2022/12/25', '2022/12/26']
    var workHoursStart = 8;
    var workHoursEnd = 17;

    let roundToNearest30 = (dateInput) => {
        const minutes = 30;
        const ms = 1000 * 60 * minutes;

        return new Date(Math.ceil(dateInput.getTime() / ms) * ms);

    }

    startDate = roundToNearest30(startDate);
    endDate = roundToNearest30(endDate);
    for (var currentDate = new Date(startDate); currentDate <= endDate; currentDate.setTime(currentDate.getTime() + 1000 * 60)) {
        var currentDateString = `${currentDate.getFullYear()}/${currentDate.getMonth() + 1}/${currentDate.getDate()}`;

        if (currentDate.getDay() != 0 && currentDate.getDay() != 6
            && currentDate.getHours() >= workHoursStart && currentDate.getHours() < workHoursEnd
            && holidays.indexOf(currentDateString) == -1
        ) {
            minutesWorked++;
        }
    }

    return (minutesWorked / 60).toFixed(1);
}


console.log(calculateBusinessDays(startDate, endDate));