(javascript или / и datejs) Попытка рассчитать два интервала дат общая зарплата. когда даты начала и окончания имеют несколько дробных дней месяца

Question

**** Вид заработной платы ежемесячно. ****

var getDiffDatesSalary = function days_between(date1,date2, monthlyBasic) {
        var dateObj1 = new Date(date1);
        var month1 = dateObj1.getMonth(); //months from 1-12
        var day1 = dateObj1.getDate();
        var year1 = dateObj1.getFullYear();
        var daysInMonth1 = Date.getDaysInMonth(year1, month1);

        var dateObj2 = new Date(date2);
        var month2 = dateObj2.getMonth(); //months from 0-11
        var day2 = dateObj2.getDate();// days from 1
        var year2 = dateObj2.getFullYear();
        var daysInMonth2 = Date.getDaysInMonth(year2, month2);

        var date1FractionDays = daysInMonth1 - day1;
        var date2FractionDays = daysInMonth2 - day2;
        var newDate1, newDate2;
        if(day1 > 1){
            var perDaySalary1 = monthlyBasic / daysInMonth1;
            var thisMonthFarctionDaysSalaryForDate1 = perDaySalary1 * date1FractionDays;
            month1 += 1; // after calculate fraction this month basic, round month from next
            newDate1 = new Date(year1,month1);
        }
        if(day2 !== daysInMonth2){
           var perDaySalary2 = monthlyBasic / daysInMonth2;
           var thisMonthFarctionDaysSalaryForDate2 = perDaySalary2 * day2;
            month2 -= 1; //after calculate fraction this month basic, round month from previous
            newDate2 = new Date(year2,month2);
        }

       // i want to calculate totalSalaryamount of date ranges
        // var totalFractionDaysSalary = thisMonthFarctionDaysSalaryForDate1 + thisMonthFarctionDaysSalaryForDate2;
        // var totalMonthsSalay = roundMonths * monthlyBasic;
        // var totalSalaryamount = totalFractionDaysSalary + totalMonthsSalay;

    };

**

result = thisMonthFarctionDaysSalaryForDate1 + thisMonthFarctionDaysSalaryForDate2 + (roundMonths * monthBasic)

результат будет getDiffDatesSalary ("2016/01/15", "2016/03/25", 1000);

516,13+806,45 + 1000 // всего: 2322,58

Или / И getDiffDatesSalary ("2015/01/15", "2016/03/25", 1000);

516,13+806,45 + (1000 * 13) // всего: 14322,58

Или / И getDiffDatesSalary ("2016/01/01", "2016/02/29", 1000);

1000 * 2 // 2000

**

Answer 1

Предлагаю разбить задачу на два раздела:

1. Получить общее количество дней
2. Рассчитать зарплату.

Это предложение использует разницу между годами, месяцами и днями и вносит поправку, если разница в днях отрицательна. Тот же день означает один день.

function getDays(date1, date2) {
    var date1Obj = new Date(date1),
        date2Obj = new Date(date2),
        totalYear = date2Obj.getFullYear() - date1Obj.getFullYear(),
        totalMonth = date2Obj.getMonth() - date1Obj.getMonth(),
        totalDay = date2Obj.getDate() - date1Obj.getDate() + 1;

    if (totalDay < 0) {
        totalMonth--;
        totalDay += new Date(date1Obj.getFullYear(), date1Obj.getMonth(), 0).getDate();
    }

    return 360 * totalYear + 30 * totalMonth + totalDay;
}

function getDiffDatesSalary(date1, date2, salaryPerMonth) {
    return getDays(date1, date2) * salaryPerMonth / 30;
}

document.write(getDiffDatesSalary("2016/01/15", "2016/03/25", 1000) + '<br>');
document.write(getDiffDatesSalary("2016/01/31", "2016/02/15", 1000) + '<br>');
document.write(getDiffDatesSalary("2016/03/20", "2016/03/20", 3000) + '<br>');

Answer 2

Я получил ответ на мой вопрос. Если кому-то нужно или улучшить этот ответ. Вот рабочие коды:

var getDiffDatesSalary = function days_between(date1,date2, monthlyBasic) {
    var dateObj1 = new Date(date1);
    var month1 = dateObj1.getMonth(); //months from 0-11
    var day1 = dateObj1.getDate();
    var year1 = dateObj1.getFullYear();
    var daysInMonth1 = Date.getDaysInMonth(year1, month1);

    var dateObj2 = new Date(date2);
    var month2 = dateObj2.getMonth(); //months from 0-11
    var day2 = dateObj2.getDate();// days from 1
    var year2 = dateObj2.getFullYear();
    var daysInMonth2 = Date.getDaysInMonth(year2, month2);
    //get number of months in two different dates;
    var diffMonths = parseInt(diffInMonths(date2,date1)) +1; //from 1-12

    var date1FractionDays = daysInMonth1 - day1; //  date1 fraction days
    var date2FractionDays = daysInMonth2 - day2; //  date2 fraction days
    var totalFractionDaysSalary= 0, fractionMonthsCount = 0, thisMonthFarctionDaysSalaryForDate1 = 0, thisMonthFarctionDaysSalaryForDate2 =0; //reset as 0;
    //when date1: day start from 01, no fraction start of the month. Otherwise calculate salary for fraction days
    if(day1 > 1){
        var perDaySalary1 = monthlyBasic / daysInMonth1;
        thisMonthFarctionDaysSalaryForDate1 = perDaySalary1 * date1FractionDays;
        fractionMonthsCount +=1;
    }
    //when date2: day end  === end Of the Month, no fraction. Otherwise calculate salary for fraction days
    if(day2 !== daysInMonth2){
       var perDaySalary2 = monthlyBasic / daysInMonth2;
        thisMonthFarctionDaysSalaryForDate2 = perDaySalary2 * day2;
        fractionMonthsCount +=1;
    }
    // both date1 date2 fraction days salary sum
    totalFractionDaysSalary = thisMonthFarctionDaysSalaryForDate1 + thisMonthFarctionDaysSalaryForDate2;
    var roundMonthsForSalary = diffMonths - fractionMonthsCount; // after less round month calculate
    // if user do wrong reset as 0. because negative month not possible
    if (roundMonthsForSalary < 0){
        roundMonthsForSalary = 0;
    }
    // round month salary calculation
    var totalSalaryForRoundMonths = roundMonthsForSalary * monthlyBasic;
// finally fraction days and round month sum to get return result.
return totalFractionDaysSalary + totalSalaryForRoundMonths;

};
// get number of months in two different dates
function diffInMonths(to,from){
    var months = to.getMonth() - from.getMonth() + (12 * (to.getFullYear() - from.getFullYear()));

    if(to.getDate() < from.getDate()){
        var newFrom = new Date(to.getFullYear(),to.getMonth(),from.getDate());
        if (to < newFrom  && to.getMonth() == newFrom.getMonth() && to.getYear() %4 != 0){
            months--;
        }
    }

    return months;
};