Calculate Business Days Jquery-CodePudding

I am using jquery and moment js to calculate Business Days. For some strange reasons 31 December 2022 is a Saturday but my code is still showing it as working day. I have a start Date of 30th December, 2022 and 1 (one) workDaysToAdd which falls on Saturday the 31st, December 2022 which is not working Business day. My code is not skipping the saturday 31st, December 2022.

function AddBusinessDays(startDate, workDaysToAdd) {
    var curDate = new Date(startDate);
    var realDaysToAdd = 0;
    while (workDaysToAdd > 0) {
        realDaysToAdd  ;
        if (IsWorkDay(curDate)) {
            workDaysToAdd--;
        }
        curDate.setDate(curDate.getDate()   1);
    }
    return realDaysToAdd;
}

function IsWorkDay(date) {
    var curDate = new Date(date);
    var dayOfWeek = curDate.getDay();
    var isWorkDay;
    if (dayOfWeek == 0 || dayOfWeek == 6) {
        isWorkDay = false;
    }
    else {
        isWorkDay = !isNationalDay(curDate);
    }
    return isWorkDay;
}

function isNationalDay(date) {
    var thisDate = new Date(date);
    var thisMoment = moment(thisDate);
    var holiday = thisMoment.holiday();
    var isHoliday = holiday != 'undefined' && holiday != null && holiday.length > 0;
    return isHoliday;
}

CodePudding user response：

Your logic is incorrect. You start on a Friday and check if it's a workday (it is) and decrement workDaysToAdd. If that started as 1, it is now 0 and your while loop exits.

Move your date increment to the top of the loop so you're checking the next day.

function AddBusinessDays(startDate, workDaysToAdd) {
  const curDate = new Date(startDate);
  let realDaysToAdd = 0;
  while (workDaysToAdd > 0) {
    curDate.setDate(curDate.getDate()   1); // move this to the top of the loop
    realDaysToAdd  ;
    if (IsWorkDay(curDate)) {
      workDaysToAdd--;
    }
  }
  return realDaysToAdd;
}

function IsWorkDay(date) {
  return date.getDay() % 6 && !isNationalDay(date);
}

function isNationalDay(date) {
  return false; // no idea where the moment.holiday() comes from
}

const startDate = new Date(Date.UTC(2022, 11, 30));
console.log("start", startDate);
console.info(AddBusinessDays(startDate, 1))