我需要最快的方法得到一周的第一天。例如:今天是11月11日,是星期四;我想要这周的第一天,也就是11月8日,一个星期一。我需要MongoDB映射函数的最快方法,有什么想法吗?


当前回答

我在用这个

function get_next_week_start() {
   var now = new Date();
   var next_week_start = new Date(now.getFullYear(), now.getMonth(), now.getDate()+(8 - now.getDay()));
   return next_week_start;
}

其他回答

查看Date.js

Date.today().previous().monday()

查看:moment.js

例子:

moment().day(-7); // last Sunday (0 - 7)
moment().day(7); // next Sunday (0 + 7)
moment().day(10); // next Wednesday (3 + 7)
moment().day(24); // 3 Wednesdays from now (3 + 7 + 7 + 7)

好处:也适用于node.js

var dt = new Date(); // current date of week
var currentWeekDay = dt.getDay();
var lessDays = currentWeekDay == 0 ? 6 : currentWeekDay - 1;
var wkStart = new Date(new Date(dt).setDate(dt.getDate() - lessDays));
var wkEnd = new Date(new Date(wkStart).setDate(wkStart.getDate() + 6));

这将会很有效。

更普遍的说法是……这将根据您指定的日期给出当前一周中的任何一天。

//返回一周中的相对日期0 = Sunday, 1 = Monday…6 =星期六 函数getRelativeDayInWeek(d,dy) { d = new日期(d); var day = d.getDay(), diff = d.getDate() - day + (day == 0 ?6: dy);//当白天是星期天时进行调整 (d.setDate(diff)); } var monday = getRelativeDayInWeek(new Date(),1); var friday = getRelativeDayInWeek(new Date(),5); console.log(星期一); console.log(周五);

该函数使用当前毫秒时间减去当前周,如果当前日期是周一,则再减去一周(javascript从周日开始计数)。

function getMonday(fromDate) {
    // length of one day i milliseconds
  var dayLength = 24 * 60 * 60 * 1000;

  // Get the current date (without time)
    var currentDate = new Date(fromDate.getFullYear(), fromDate.getMonth(), fromDate.getDate());

  // Get the current date's millisecond for this week
  var currentWeekDayMillisecond = ((currentDate.getDay()) * dayLength);

  // subtract the current date with the current date's millisecond for this week
  var monday = new Date(currentDate.getTime() - currentWeekDayMillisecond + dayLength);

  if (monday > currentDate) {
    // It is sunday, so we need to go back further
    monday = new Date(monday.getTime() - (dayLength * 7));
  }

  return monday;
}

当一周从一个月延伸到另一个月(也包括几年)时,我对它进行了测试,它似乎可以正常工作。