Common date-time functions in JS development

Common date-time functions in JS development
String to date type, Date.prototype.isleapyear judge leap year
Date.prototype.format Date format
Date.prototype.dateadd Date Calculation
Date.prototype.datediff Comparison Date Difference
Date.prototype.tostring Date-turn string
Date.prototype.toarray date split into arrays
Date.prototype.datepart some information about the date
Date.prototype.maxdayofdate the maximum number of days of the month from which the date is taken
Date.prototype.weeknumofyear the first weeks of the year in which the date is judged
Stringtodate String Turn Date type
Isvaliddate Validation Date Validity
Checkdatetime Full Date Time check
Daysbetween Date Days Bad

function DateAdd (interval,number,date)


{


/*


* Function: To achieve the DATEADD function of VBScript.


* Parameter: interval, a string expression representing the time interval to add.


* Parameter: number, numeric expression, representing the amount of time interval to add.


* Parameter: Date, Time object.


* Return: A new Time object.


* var now = new Date ();


* var newdate = DATEADD ("D", 5,now);


*---------------DateAdd (interval,number,date)-----------------


*/


Switch (interval)


{


Case "Y": {


Date.setfullyear (Date.getfullyear () +number);


return date;


Break


}


Case "Q": {


Date.setmonth (Date.getmonth () +number*3);


return date;


Break


}


Case "M": {


Date.setmonth (Date.getmonth () +number);


return date;


Break


}


Case "W": {


Date.setdate (Date.getdate () +number*7);


return date;


Break


}


Case "D": {


Date.setdate (Date.getdate () +number);


return date;


Break


}


Case "H": {


Date.sethours (Date.gethours () +number);


return date;


Break


}


Case "M": {


Date.setminutes (Date.getminutes () +number);


return date;


Break


}


Case "S": {


Date.setseconds (Date.getseconds () +number);


return date;


Break


}


Default: {


Date.setdate (D.getdate () +number);


return date;


Break


}


}


}

var now = new Date ();
Plus five days.
var newdate = DATEADD ("D", 5,now);
Alert (newdate.tolocaledatestring ())
Plus two months.
Newdate = DateAdd ("M", 2,now);
Alert (newdate.tolocaledatestring ())
Plus one year
Newdate = DATEADD ("y", 1,now);
Alert (newdate.tolocaledatestring ())

//---------------------------------------------------


Judging leap years


//---------------------------------------------------


Date.prototype.isleapyear = function ()


{


Return (0==this.getyear ()%4&& (This.getyear ()%100!=0) | | (This.getyear ()%400==0));


}





//---------------------------------------------------


Date formatting


Format Yyyy/yyyy/yy/yy represents year


Mm/m Month


W/W Week


dd/dd/d/d Date


hh/hh/h/h time


mm/m minutes


SS/SS/S/S seconds


//---------------------------------------------------


Date.prototype.format = function (FORMATSTR)


{


var str = FORMATSTR;


var week = [' Day ', ' one ', ' two ', ' three ', ' four ', ' five ', ' six '];





Str=str.replace (/yyyy|yyyy/,this.getfullyear ());


Str=str.replace (/yy|yy/, (this.getyear ()%) >9? ( This.getyear ()%). ToString (): ' 0 ' + (this.getyear ()% 100));





Str=str.replace (/mm/,this.getmonth () >9?this.getmonth (). ToString (): ' 0 ' + this.getmonth ());


Str=str.replace (/m/g,this.getmonth ());





Str=str.replace (/w|w/g,week[this.getday ());





Str=str.replace (/dd|dd/,this.getdate () >9?this.getdate (). ToString (): ' 0 ' + this.getdate ());


Str=str.replace (/d|d/g,this.getdate ());





Str=str.replace (/hh|hh/,this.gethours () >9?this.gethours (). ToString (): ' 0 ' + this.gethours ());


Str=str.replace (/h|h/g,this.gethours ());


Str=str.replace (/mm/,this.getminutes () >9?this.getminutes (). ToString (): ' 0 ' + this.getminutes ());


Str=str.replace (/m/g,this.getminutes ());





Str=str.replace (/ss|ss/,this.getseconds () >9?this.getseconds (). ToString (): ' 0 ' + this.getseconds ());


Str=str.replace (/s|s/g,this.getseconds ());





return str;


}





//+---------------------------------------------------


//| The number of days for two time difference date format is YYYY-MM-DD


//+---------------------------------------------------


function Daysbetween (dateone,datetwo)


{


var onemonth = dateone.substring (5,dateone.lastindexof ('-'));


var oneday = dateone.substring (Dateone.length,dateone.lastindexof ('-') +1);


var oneyear = dateone.substring (0,dateone.indexof ('-'));





var twomonth = datetwo.substring (5,datetwo.lastindexof ('-'));


var twoday = datetwo.substring (Datetwo.length,datetwo.lastindexof ('-') +1);


var twoyear = datetwo.substring (0,datetwo.indexof ('-'));





var cha= (Date.parse (onemonth+ '/' +oneday+ '/' +oneyear ')-date.parse (twomonth+ '/' +twoday+ '/' +twoyear))/86400000);


Return Math.Abs (CHA);


}








//+---------------------------------------------------


//| Date Calculation


//+---------------------------------------------------


Date.prototype.dateadd = function (strinterval, number) {


var dttmp = this;


Switch (strinterval) {


Case ' s ': return new Date (Date.parse (dttmp) + (1000 * number));


Case ' n ': return new Date (Date.parse (dttmp) + (60000 * number));


Case ' H ': return new Date (Date.parse (dttmp) + (3600000 * number));


Case ' d ': return new Date (Date.parse (dttmp) + (86400000 * number));


Case ' W ': Return new Date (Date.parse (dttmp) + ((86400000 * 7) * number));


Case ' Q ': return new Date (Dttmp.getfullyear (), (Dttmp.getmonth ()) + number*3, Dttmp.getdate (), dttmp.gethours (), Dttmp.getminutes (), dttmp.getseconds ());


Case ' m ': return new Date (Dttmp.getfullyear (), (Dttmp.getmonth ()) + number, dttmp.getdate (), dttmp.gethours (), Dttmp.getminutes (), dttmp.getseconds ());


Case ' Y ': return new Date ((Dttmp.getfullyear () + number), Dttmp.getmonth (), Dttmp.getdate (), dttmp.gethours (), Dttmp.getminutes (), dttmp.getseconds ());


}


}





//+---------------------------------------------------


//| Compare Date Difference dtend format is a date type or a valid date format string


//+---------------------------------------------------


Date.prototype.datediff = function (Strinterval, dtend) {


var dtstart = this;


if (typeof dtend = = ' string ')//if the string is converted to a date type


{


Dtend = Stringtodate (dtend);


}


Switch (strinterval) {


Case ' s ': Return parseint ((Dtend-dtstart)/1000);


Case ' n ': Return parseint ((Dtend-dtstart)/60000);


Case ' H ': Return parseint ((dtend-dtstart)/3600000);


Case ' d ': Return parseint ((dtend-dtstart)/86400000);


Case ' W ': Return parseint (Dtend-dtstart)/(86400000 * 7));


Case ' m ': Return (Dtend.getmonth () +1) + ((Dtend.getfullyear ()-dtstart.getfullyear ()) *12)-(Dtstart.getmonth () +1);


Case ' Y ': return dtend.getfullyear ()-dtstart.getfullyear ();


}


}





//+---------------------------------------------------


//| Date output string that overloads the system's ToString method


//+---------------------------------------------------


date.prototype.tostring = function (Showweek)


{


var mydate= this;


var str = mydate.tolocaledatestring ();


if (Showweek)


{


var week = [' Day ', ' one ', ' two ', ' three ', ' four ', ' five ', ' six '];


STR + + ' Week ' + week[mydate.getday ()];


}


return str;


}





//+---------------------------------------------------


//| Validation of date legality


//| Format is: YYYY-MM-DD or YYYY/MM/DD


//+---------------------------------------------------


function Isvaliddate (DATESTR)


{


var sdate=datestr.replace (/(^s+|s+$)/g, ""); Go to both sides of the space;


if (sdate== ') return true;


If the format satisfies the yyyy-(/) mm-(/) DD or yyyy-(/) m (/) DD or yyyy-(/) m (/) d or yyyy-(/) mm-(/) d, replace with '


In the database tutorial, the legal date can be: Yyyy-mm/dd (2003-3/21), and the database is automatically converted to YYYY-MM-DD format


var s = sdate.replace (/[d]{4,4}[-/]{1}[d]{1,2}[-/]{1}[d]{1,2}/g, ");


if (s== ')//description format meets YYYY-MM-DD or YYYY-M-DD or yyyy-m-d or yyyy-mm-d


{


var t=new date (Sdate.replace (/-/g, '/'));


var ar = sdate.split (/[-/:]/);


if (Ar[0]!= t.getyear () | | ar[1]!= t.getmonth () +1 | | ar[2]!= t.getdate ())


{


Alert (' Wrong date format! The format is: Yyyy-mm-dd or YYYY/MM/DD. Notice leap year. ');


return false;


}


}


Else


{


Alert (' Wrong date format! The format is: Yyyy-mm-dd or YYYY/MM/DD. Notice leap year. ');


return false;


}


return true;


}





//+---------------------------------------------------


//| Date Time Check


//| Format is: Yyyy-mm-dd hh:mm:ss


//+---------------------------------------------------


function Checkdatetime (str)


{


var reg =/^ (d+)-(d{1,2})-(D{1,2}) (d{1,2}):(d{1,2}):(d{1,2}) $/;


var r = Str.match (reg);


if (r==null) return false;


R[2]=r[2]-1;


var d= new Date (r[1],r[2],r[3],r[4],r[5],r[6]);


if (D.getfullyear ()!=r[1]) return false;


if (D.getmonth ()!=r[2]) return false;


if (D.getdate ()!=r[3]) return false;


if (D.gethours ()!=r[4]) return false;


if (D.getminutes ()!=r[5]) return false;


if (D.getseconds ()!=r[6]) return false;


return true;


}





//+---------------------------------------------------


//| Split dates into groups


//+---------------------------------------------------


Date.prototype.toarray = function ()


{


var mydate = this;


var myarray = array ();


Myarray[0] = Mydate.getfullyear ();


MYARRAY[1] = Mydate.getmonth ();


MYARRAY[2] = Mydate.getdate ();


MYARRAY[3] = mydate.gethours ();


MYARRAY[4] = Mydate.getminutes ();


MYARRAY[5] = Mydate.getseconds ();


return myarray;


}





//+---------------------------------------------------


//| Get Date data information


//| Parameter interval representing data types


//| Y year M month D Day W week WW Week h when N minutes s sec


//+---------------------------------------------------


Date.prototype.datepart = function (interval)


{


var mydate = this;


var partstr= ';


var week = [' Day ', ' one ', ' two ', ' three ', ' four ', ' five ', ' six '];


Switch (interval)


{


Case ' y ':p artstr = Mydate.getfullyear ();


Case ' m ':p artstr = Mydate.getmonth () +1;break;


Case ' d ':p artstr = Mydate.getdate ();


Case ' W ':p artstr = Week[mydate.getday ()];break;


Case ' ww ':p artstr = Mydate.weeknumofyear ();


Case ' h ':p artstr = mydate.gethours ();


Case ' n ':p artstr = Mydate.getminutes ();


Case ' s ':p artstr = Mydate.getseconds ();


}


return partstr;


}





//+---------------------------------------------------


//| Gets the maximum number of days of the month where the current date is


//+---------------------------------------------------


Date.prototype.maxdayofdate = function ()


{


var mydate = this;


var ary = Mydate.toarray ();


var date1 = (new Date (ary[0],ary[1]+1,1));


var date2 = date1.dateadd (1, ' m ', 1);


var result = DateDiff (Date1.format (' Yyyy-mm-dd '), Date2.format (' yyyy-mm-dd '));


return result;


}





//+---------------------------------------------------


//| To get the current date the week is the week ordinal of the year


//+---------------------------------------------------


Date.prototype.weeknumofyear = function ()


{


var mydate = this;


var ary = Mydate.toarray ();


var year = ary[0];


var month = ary[1]+1;


var day = ary[2];


document.write (' < script language=vbscript> n ');


document.write (' mydate = DateValue (' +month+ '-' +day+ '-' +year+ ') n ');


document.write (' result = datepart (' ww ', mydate) n ');


document.write (' n ');


return result;


}





//+---------------------------------------------------


//| string is converted to date type


//| Format mm/dd/yyyy mm-dd-yyyy yyyy/mm/dd yyyy-mm-dd


//+---------------------------------------------------


function Stringtodate (DATESTR)


{





var converted = Date.parse (DATESTR);


var mydate = new Date (converted);


if (isNaN (mydate))


{


var Delimcahar = datestr.indexof ('/')!=-1? ' /':'-';


var arys= datestr.split ('-');


MyDate = new Date (Arys[0],--arys[1],arys[2]);


}


return mydate;


}