给定日期(m/d/yyyy)确定它是否是"月的第三个星期二"等

Question

经过几次搜索,我找不到我想要的东西.我正在使用jquery datepicker返回一个看起来像的日期字符串,Day, Month Date, YYYY我正在寻找一个库或一些方法,将其转换为 the second Tuesday of the month,或the fourth Thursday of the month.到目前为止它似乎是jquery的,prettyDate并EasyDate没有我正在寻找的功能,我希望避免手动这样做!

谢谢,亚历克斯

Answer 1

您不需要日期库 - 只需取日期,除以7并向上舍入.

//format: Day, Month Date, YYYY
var ordinals = ["", "first", "second", "third", "fourth", "fifth"];
var date = "Friday, May 10, 2013";
var tokens = date.split(/[ ,]/);
// tokens = ["Friday", "", "May", "10", "", "2013"];
console.log( "The " + ordinals[Math.ceil(tokens[3]/7)] + " " + tokens[0] + " of the month");

Answer 2

如果 momentjs 不适合您，这是我当天使用的脚本（尽管我确实认为 momentjs 是更好的解决方案）。

/*
Parameters:
index: n'th occurrence of the specified day
day: daynumber - javascript way where sunday is 0 and is saturday is 6
month: javascript way which is 0-11 [optional - defaults to current]
year: Full year - four digits [optional - defaults to current]
*/
function getNthDayOfMonth(index,day,month,year){
// Create date object
var date = new Date();
// Set to first day of month
date.setDate(1);
// If supplied - set the month  
if(month!==''&&month!==undefined){
    // Set month
    date.setMonth(month);
}else{
    month = date.getMonth();
}
// If supplied - set the year   
if(year!==''&&year!==undefined){
    // Set year
    date.setFullYear(year);
}else{
    year = date.getFullYear();
}
// Find daynumber
firstDay = date.getDay();
// Find first friday.
while(date.getDay()!=day){      
    date.setDate(date.getDate()+1) ;
}
switch(index){
    case 2:
        date.setDate(date.getDate()+7);         
    break;
    case 3:
        date.setDate(date.getDate()+14);                
    break;
    case 4:
        date.setDate(date.getDate()+21);
    break;
    case 5:
        date.setDate(date.getDate()+28);
        if(date.getMonth()!==month){
            date = null;
        }
    break;
}
return date;
}