前端基础（三十）：自定义周度计算

需求

实现

let weeks = [];
for (let i = 1970; i <= 2060; i++) {

    let year = i;
    let date = new Date(`${year}-1-1`);

    let obj = {
        label: year,
        children: [],
    }

    // 当前年第一个周一日期的时间戳
    let time;
    if (date.getDay() === 1) {
        time = new Date(`${year}-1-${date.getDay()} 00:00:00`).getTime();
    } else if (date.getDay() > 4) {
        time = new Date(`${year}-1-${9 - date.getDay()} 00:00:00`).getTime();
    } else if (date.getDay() <= 4) {
        time = new Date(`${year}-1-${9 - date.getDay()} 00:00:00`).getTime() - 7 * 24 * 3600000;
    }

    let count = 0;

    for (let j = 1; j <= 53; j++) {

        let startTime = time + (j - 1) * 7 * 24 * 3600000;
        let start = new Date(startTime);
        let endTime = startTime + 6 * 24 * 3600000;
        let end = new Date(endTime);

        if (j === 1) {
            if (
                (startTime - new Date(`${year}-1-1 00:00:00`).getTime() <= 3 * 24 * 3600000)
                &&
                (startTime - new Date(`${year}-1-1 00:00:00`).getTime() > 0)
            ) {
                count = 1;
            } else {
                count = 0;
            }
        }
        if (j === 52 || j === 53) {
            if (new Date(`${year}-12-31 00:00:00`).getTime() - startTime < 4 * 24 * 3600000) {
                break;
            }
        }

        obj.children.push({
            label: `week${count + j}`,
            start: `${start.getFullYear()}/${start.getMonth() + 1}/${start.getDate()}`,
            end: `${end.getFullYear()}/${end.getMonth() + 1}/${end.getDate()}`
        })
    }

    weeks.push(obj)
}
console.log(weeks);