javascript - 本季度的第几周，使用 javascript

Question

我正在尝试想出一种方法来查找季度中的第几周，并偏移两周。我们在季度的第三个星期六(2011 年 10 月 15 日、2012 年 1 月 21 日等)发布季度软件版本。有办法获取这些信息吗？

例如，本周将是该季度的第 13 周。

Answer 1

function getQuarterWeek(d) {
    // Convert to UTC to avoid DST changes.
    d = new Date(Date.UTC(d.getFullYear(), d.getMonth(), d.getDay()));
    // For previous Saturday you would normally add one here.
    // But we want to go back two weeks, so subtract 14.
    d.setUTCDate(d.getUTCDate() - 13);
    d.setUTCDate(d.getUTCDate() - d.getUTCDay() - 1);
    // Save the timestamp of this Saturday.
    var s = d.getTime();
    // Now get the first day of the quarter.
    d.setUTCDate(1);
    d.setUTCMonth(d.getUTCMonth() - d.getUTCMonth() % 3);
    // And find the following Saturday.
    d.setUTCDate(7 - d.getUTCDay());
    // Convert the time difference to weeks.
    return (d.getTime() - s) / 604800000 + 1;
}