perhaps someone can give me some good ideas of how to accomplish this.

I would like to get the weekdays for either the first two weeks or last two weeks of a month based on the current date.

So if we are using the following to get the date today (2022-07-06)

    const current = new Date();
    const date = `${current.getFullYear()}-${current.getMonth() 1}-${current.getDate()}`;

The results I would be looking for are

const firstHalfWeekdates = ['2022-07-04', '2022-07-05', '2022-07-06', '2022-07-07', '2022-07-08', '2022-07-11', '2022-07-12', '2022-07-13', '2022-07-14', '2022-07-15']

and if the date fell on 2022-07-18 it would return

const secondHalfWeekdates = ['2022-07-18', '2022-07-19', '2022-07-20', '2022-07-21', '2022-07-22', '2022-07-25', '2022-07-26', '2022-07-27', '2022-07-28', '2022-07-29']

Also happy to use a library

CodePudding user response：

Maybe this can give you a start. It returns the weekdays, divided by week.

I was trying to do everything you asked, but I ran into some problems, for example you want to divide the month into 4 weeks, 2 in the first half and 2 in the second half, but for example this month now July/2022, has a week that has only one weekday (July 1º), but in your expected results you ignored this week, whats the logic to ignore weeks? It has to be a complete week with 5 weekdays? What about last month Jun/2022, there were not 4 complete weeks, there were only 3 complete weeks, the other 2 has 3 and 4 days respectively, which week would you ignore in this case?

function isWeekDay(day) {
    return day != 0 && day != 6;
}

function formatDateYYYYMMDD(date) {
    let dateString = date.toLocaleDateString('en-GB');
    let year = dateString.substring(6, 10);
    let month = dateString.substring(3, 5);
    let day = dateString.substring(0, 2);
    return `${year}-${month}-${day}`;
}

function getWeekdaysOfTheCurrentMonthDividedByWeek() {
    let currentDate = new Date();
    let month = currentDate.getMonth();
    let weekdays = [];
    let tempDate = new Date(currentDate.getFullYear(), currentDate.getMonth(), 1);
    let week = [];

    while (tempDate.getMonth() == month) {
        if (isWeekDay(tempDate.getDay())) {
            week.push(formatDateYYYYMMDD(tempDate));
        } else if (week.length > 0) {
            weekdays.push(week);
            week = [];
        }
        tempDate.setDate(tempDate.getDate()   1);
    }

    return weekdays;
}

console.log(getWeekdaysOfTheCurrentMonthDividedByWeek());

CodePudding user response：

You could split the month up into calendar weeks. (e.g. for July 2022 it would be: July 1-2, 3-9, 10-16, ect…)

Then, depending on the day, take either the first or second half of the weeks.

Iterate over the filtered weeks, counting the weekdays.

I choose to include the third week in the first half of the month if there were 5 weeks, but you could change that by changing Math.ceil to Math.floor

/**
 * Get the last item in an array, or undefined if the array is empty.
 * @template T
 * @param {[T]} array
 * @returns {T|undefined}
 */
const lastItem = array => array[array.length - 1];

const getWeekdays = current => {
    /** @type {[[Date]]} */
    const weeks = [];

    // Get the weeks
    /**
     * Get the calendar week of the given date.
     * @param {Date} firstDay The first day of the week.
     * @returns {[Date]}
     */
    const getWeek = firstDay => {
        /** @type {[Date]} */
        let days = [];

        let dateToTest = new Date(firstDay);
        // Continue until the end of the week or month, whichever comes first.
        while (
            dateToTest.getDay() <= 6 &&
            dateToTest.getMonth() == firstDay.getMonth()
        ) {
            days.push(new Date(dateToTest));
            dateToTest.setDate(dateToTest.getDate()   1);
        }

        return days;
    };

    // The first day of the month
    const firstDay = new Date(current.getFullYear(), current.getMonth());
    let dateToTest = new Date(firstDay);
    do {
        weeks.push(getWeek(dateToTest));
        dateToTest = new Date(lastItem(lastItem(weeks)));
        dateToTest.setDate(dateToTest.getDate()   1);
    } while (dateToTest.getMonth() == firstDay.getMonth());

    // Filter to half of the month
    // Get the week of the given date
    let currentWeek = 0;
    weekLoop: for (let i = 0; i < weeks.length; i  ) {
        const week = weeks[i];
        for (const day of week) {
            if (day == current) {
                currentWeek = i;
                break weekLoop;
            }
        }
    }

    /** @type {[[Date]]} */
    let weeksInHalf = [];

    const numOfWeeksInFirstHalf = Math.ceil(weeks.length / 2),
        numOfWeeksInSecondHalf = weeks.length - numOfWeeksInFirstHalf;

    for (
        let i = 0;
        i <
        (currentWeek < numOfWeeksInFirstHalf
            ? numOfWeeksInFirstHalf
            : numOfWeeksInSecondHalf);
        i  
    ) {
        weeksInHalf.push(weeks[i]);
    }

    // Filter out weekends
    // Format dates
    return weeksInHalf
        .flat()
        .filter(day => day.getDay() > 0 && day.getDay() < 6)
        .map(
            day => `${day.getFullYear()}-${day.getMonth()   1}-${day.getDate()}`
        );
};

// Tests
for (let i = 0; i < 12; i  ) {
    const weekdays = getWeekdays(new Date(2022, i));
    weekdays.forEach(dateString => {
        const [year, month, day] = dateString.split("-");
        const date = new Date(year, month - 1, day);
        if (date.getDay() == 0 || date.getDay() == 6)
            throw new Error("Invalid day: (day)");
        else console.log(dateString)
    });
}