传入两个Date类型的日期,求出它们相隔多少天。
var getDatePeriod = function (start,finish){
return Math.abs(start*1-finish*1)/60/60/1000/24;
}
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传入一个Date类型的日期,求出它所在月的第一天。
var getFirstDateInMonth= function (date){
return new Date(date.getFullYear(),date.getMonth(),1);
}
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传入一个Date类型的日期,求出它所在月的最后一天。
var getLastDateInMonth= function (date){
return new Date(date.getFullYear(),date.getMonth()+1,0);
}
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传入一个Date类型的日期,求出它所在季度的第一天。
var getFirstDateInQuarter= function (date){
return new Date(date.getFullYear(),~~(date.getMonth()/3)*3,1);
}
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传入一个Date类型的日期,求出它所在季度的最后一天。
var getFirstDateInQuarter= function (date){
return new Date(date.getFullYear(),~~(date.getMonth()/3)*3+3,0);
}
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判断是否为闰年。
Date.prototype.isLeapYear = function () {
return new Date( this .getFullYear(),2,0).getDate() == 29;
}
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取得当前周某星期几的Date对象,参数为星期号(星期一为1,星期二为2……星期日为7)。
var getWeekDay = function (num){
var now = new Date( new Date.setHours(0,0,0,0));
var day = now.getDay() || 7;
var delta = Math.abs(day-num) * 60 * 60 * 1000 * 24;
if (day > num){
return new Date(now - delta);
} else if (day < num){
return new Date(now + delta);
} else {
return now;
}
}
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function daysInMonth ( year, month ) {
var num = new Date();
num.setFullYear( year, (month == 12) ? 1 : month + 1, 0 );
return num.getDate();
}
function dateDif( inDate1, inDate2 ) {
var ret = new Array();
var date1 = new Date( (inDate1 <= inDate2) ? inDate1 : inDate2 );
var date2 = new Date( (inDate1 <= inDate2) ? inDate2 : inDate1 );
var temp1 = new Date( date2.getFullYear(), date1.getMonth(), date1.getDate() );
var temp2 = new Date( date2.getFullYear(), date2.getMonth() - (date1.getDate() > date2.getDate() ? 1 : 0 ), date1.getDate() );
ret[0] = date2.getFullYear() - date1.getFullYear() - (date2 < temp1 ? 1 : 0);
ret[1] = temp2.getMonth() - temp1.getMonth() + (temp1.getMonth() > temp2.getMonth() ? 12 : 0 );
ret[2] = date2.getDate() - temp2.getDate() + (temp2.getDate() > date2.getDate() ? daysInMonth(temp2.getFullYear(), temp2.getMonth()) : 0);
return ret;
}
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function getDaysInMonth1(date) {
switch (date.getMonth()) {
case 0:
case 2:
case 4:
case 6:
case 7:
case 9:
case 11:
return 31;
case 1:
var y = date.getFullYear();
return y % 4 == 0 && y % 100 != 0 || y % 400 == 0 ? 29 : 28;
default :
return 30;
}
}
var getDaysInMonth2 = ( function () {
var daysInMonth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
function isLeapYear(date) {
var y = date.getFullYear();
return y % 4 == 0 && y % 100 != 0 || y % 400 == 0;
}
return function (date) {
var m = date.getMonth();
return m == 1 && isLeapYear(date) ? 29 : daysInMonth[m];
};
})();
function getDaysInMonth3(date) {
return new Date(date.getFullYear(),date.getMonth()+1,0).getDate();
}
function test(f) {
var d = new Date;
var date = new Date(2000, 1, 2);
for ( var i = 0; i < 80000; i++)
f(date);
return ( new Date - d);
}
function test2(f) {
var d = new Date;
for ( var i = 0; i < 80000; i++)
f(d);
return ( new Date - d);
}
alert([test(getDaysInMonth1), test(getDaysInMonth2), test(getDaysInMonth3)]);
alert([test2(getDaysInMonth1), test2(getDaysInMonth2), test2(getDaysInMonth3)]);
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判定字符串2009/2/23(或者2009/02/23)是否合法
var test = function (str){
var arr = str.split( "/" )
var m = Number(arr[1])-1
var d = new Date(Number(arr[0]),m,Number(arr[2]) )
if (isNaN(d))
return false ;
if (isNaN(d.getDate()))
return false ;
return d.getMonth() === m
}
test( "2009/2/25" )
test( "2009/2/29" )
test( "2009/2/32" )
test( "2009/02/15" )
function test(s){
return /^(\d{4})\/(\d\d?)\/(\d\d?)$/.test(s) && s.replace(/^(\d{4})\/(\d\d?)\/(\d\d?)$/, function (a,b,c,d){
var m = parseInt(c,10);
if (m < 1 || m > 12) return false ;
var d = parseInt(d,10);
return d > 0 && d <= (
m == 2 ? (m = parseInt(b, 10), m % 4 == 0 && m % 100 != 0 || m % 400 == 0) ? 29 : 28 :
m == 4 || m == 6 || m == 9 || m == 11 ? 30 : 31);
});
}
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