Javascript Date object Date Extension Method

Today, I have excerpted some methods related to date operations in js on the Internet. I 'd like to share with you. Copy codeThe Code is as follows: <script type = "text/javascript">
Date. prototype. Format = function (fmt)
{
// Author: meizz
Var o =
{
"M +": this. getMonth () + 1, // month
"D +": this. getDate (), // day
"H +": this. getHours (), // hour
"M +": this. getMinutes (), // minute
"S +": this. getSeconds (), // second
"Q +": Math. floor (this. getMonth () + 3)/3), // quarter
"S": this. getMilliseconds () // millisecond
};
If (/(y +)/. test (fmt ))
Fmt = fmt. replace (RegExp. $1, (this. getFullYear () + ""). substr (4-RegExp. $1. length ));
For (var k in o)
If (new RegExp ("(" + k + ")"). test (fmt ))
Fmt = fmt. replace (RegExp. $1, (RegExp. $1. length = 1 )? (O [k]): ("00" + o [k]). substr ("" + o [k]). length )));
Return fmt;
}
Date. prototype. addDays = function (d)
{
This. setDate (this. getDate () + d );
};
Date. prototype. addWeeks = function (w)
{
This. addDays (w * 7 );
};
Date. prototype. addMonths = function (m)
{
Var d = this. getDate ();
This. setMonth (this. getMonth () + m );
If (this. getDate () <d)
This. setDate (0 );
};
Date. prototype. addYears = function (y)
{
Var m = this. getMonth ();
This. setFullYear (this. getFullYear () + y );
If (m <this. getMonth ())
{
This. setDate (0 );
}
};
// Test var now = new Date (); now. addDays (1); // add or subtract a Date operation alert (now. Format ("yyyy-MM-dd "));
Date. prototype. dateDiff = function (interval, endTime)
{
Switch (interval)
{
Case "s": // calculate the second difference
Return parseInt (endTime-this)/1000 );
Case "n": // calculate the Score Difference
Return parseInt (endTime-this)/60000 );
Case "h": // calculate the time difference
Return parseInt (endTime-this)/3600000 );
Case "d": // calculate the daily difference
Return parseInt (endTime-this)/86400000 );
Case "w": // calculate the variance
Return parseInt (endTime-this)/(86400000*7 ));
Case "m": // calculate the monthly difference
Return (endTime. getMonth () + 1) + (endTime. getFullYear ()-this. getFullYear () * 12)-(this. getMonth () + 1 );
Case "y": // calculate the year difference
Return endTime. getFullYear ()-this. getFullYear ();
Default: // token has a token
Return undefined;
}
}
// Test var starTime = new Date ("2007/05/12 07:30:00"); var endTime = new Date ("2008/06/12 08:32:02"); document. writeln ("second difference:" + starTime. dateDiff ("s", endTime) + "<br>"); document. writeln ("difference:" + starTime. dateDiff ("n", endTime) + "<br>"); document. writeln ("Time Difference:" + starTime. dateDiff ("h", endTime) + "<br>"); document. writeln ("day difference:" + starTime. dateDiff ("d", endTime) + "<br>"); document. writeln ("latency difference:" + starTime. dateDiff ("w", endTime) + "<br>"); document. writeln ("month difference:" + starTime. dateDiff ("m", endTime) + "<br>"); document. writeln ("year difference:" + starTime. dateDiff ("y", endTime) + "<br> ");
</Script>

The specific extension method is as follows:
ParseCHS -- static method. Parse common Chinese dates and return date objects.
Add -- date addition and subtraction. [Note: This function also has a BUG when being uploaded. Please download and change the first line in this function to "var regExp =/^ \ d + $/;" to "var regExp =/^ ([+-])? \ D + $/; ", otherwise the subtraction cannot be done.]
DateDiff -- date difference. Returns the absolute value of the difference between the start date and the current date.
GetFirstWeekDays -- get the number of days in the first week of the year of the current date.
GetLastWeekDays -- get the number of days of the last week in the year of the current date.
GetWeeksOfYear -- Obtain the week number Of The Year of the current date.
GetWeek -- Obtain the week number of the year for the current date. Returns an integer.
GetSeason -- obtains the quarter of the year where the current date is located. Returns a quarter integer.
For detailed comments and parameters, see the comments in the JS file.Copy codeThe Code is as follows :/*
========================================================== ========================================================== =====
Description: Date object extension. Including common Chinese Date Format Parsing, addition and subtraction operations, date difference, weekly operations, and seasonal operations.
Author: Dezwen.
Date: 2009-5-30.
========================================================== ========================================================== =====
*/
Date. parseCHS = function (dateString ){
/// <Summary>
/// Parse common Chinese dates and return date objects.
/// </Summary>
/// <Param name = "dateString" type = "string">
/// Date string. The formats include: "xxxx (xx)-xx: xx", "xxxx (xx). xx. xx: xx ",
/// "Xxxx (xx)-xx: xx seconds"
/// </Param>
Var regExp1 =/^ \ d {4}-\ d {1, 2}-\ d {1, 2} (\ d {1, 2 }:\ d {1, 2 }: \ d {1, 2 })? $ /;
Var regExp2 =/^ \ d {4 }\. \ d {1, 2 }\. \ d {1, 2} (\ d {1, 2}: \ d {1, 2}: \ d {1, 2 })? $ /;
Var regExp3 =/^ \ d {4} year \ d {1, 2} month \ d {1, 2} Day (\ d {1, 2} hour \ d {1, 2} minute \ d {1, 2} seconds )? $ /;
If (regExp1.test (dateString )){}
Else if (regExp2.test (dateString )){
DateString = dateString. replace (/\./g ,"-");
}
Else if (regExp3.test (dateString )){
DateString = dateString. replace ("year", "-"). replace (
"Month", "-"). replace ("day", ""). replace ("Hour", ":"). replace ("Minute ",":"
). Replace ("seconds ","");
}
Else {
The format of the parameter value passed to Date. parseCHS by throw is incorrect. Please pass a valid date format string as the parameter. ";
}
Var date_time = dateString. split ("");
Var date_part = date_time [0]. split ("-");
Var time_part = (date_time.length> 1? Date_time [1]. split (":"):"");
If (time_part = ""){
Return new Date (date_part [0], date_part [1]-1, date_part [2]);
}
Else {
Return new Date (date_part [0], date_part [1]-1, date_part [2], time_part [0], time_part [1], time_part [2]);
}
}
Date. prototype. add = function (datepart, number, returnNewObjec ){
/// <Summary>
/// Add or subtract a date.
/// If the returnNewObjec parameter is set to true, the operation result is returned by a new date object, and the original date object remains unchanged,
/// Otherwise, the original date object is returned, and the value of the original date object is the operation result.
/// </Summary>
/// <Param name = "datepart" type = "string">
/// Date addition and subtraction:
/// Year, yy, yyyy -- Year
/// Quarter, qq, q-quarter
/// Month, mm, m -- Month
/// Dayofyear, dy, y -- day
/// Day, dd, d -- Day
/// Week, wk, ww -- Week
/// Hour, hh -- Hour
/// Minute, mi, n -- minute
/// Second, ss, s -- seconds
/// Millisecond, MS-millisecond
/// </Param>
/// <Param name = "number" type = "int">
/// Quantity to be added or subtracted
/// </Param>
/// <Param name = "returnNewObjec" type = "bool">
/// Whether to return a new date object. If the parameter is true, a new date object is returned; otherwise, the current date object is returned.
/// </Param>
/// <Returns type = "Date">
/// Return a date object
/// </Returns>
Var regExp =/^ \ d + $ /;
If (regExp. test (number )){
Number = parseInt (number );
}
Else {number = 0 ;}
Datepart = datepart. toLowerCase ();
Var tDate;
If (typeof (returnNewObjec) = "boolean "){
If (returnNewObjec = true ){
TDate = new Date (this );
}
Else {tDate = this ;}
}
Else {tDate = this ;}

Switch (datepart ){
Case "year ":
Case "yy ":
Case "yyyy ":
TDate. setFullYear (this. getFullYear () + number );
Break;
Case "quarter ":
Case "qq ":
Case "q ":
TDate. setMonth (this. getMonth () + (number * 3 ));
Break;
Case "month ":
Case "mm ":
Case "m ":
TDate. setMonth (this. getMonth () + number );
Break;
Case "dayofyear ":
Case "dy ":
Case "y ":
Case "day ":
Case "dd ":
Case "d ":
TDate. setDate (this. getDate () + number );
Break;
Case "week ":
Case "wk ":
Case "ww ":
TDate. setDate (this. getDate () + (number * 7 ));
Break;
Case "hour ":
Case "hh ":
TDate. setHours (this. getHours () + number );
Break
Case "minute ":
Case "mi ":
Case "n ":
TDate. setMinutes (this. getMinutes () + number );
Break
Case "second ":
Case "ss ":
Case "s ":
TDate. setSeconds (this. getSeconds () + number );
Break;
Case "millisecond ":
Case "ms ":
TDate. setMilliseconds (this. getMilliseconds () + number );
Break;
}
Return tDate;
}
Date. prototype. dateDiff = function (datepart, beginDate ){
/// <Summary>
/// Returns the absolute value of the difference between the start date and the current date.
/// </Summary>
/// <Param name = "datepart" type = "string">
/// Date addition and subtraction:
/// Year, yy, yyyy -- Year;
/// Quarter, qq, q-quarter
/// Month, mm, m -- Month
/// Dayofyear, dy, y -- day
/// Day, dd, d -- Day
/// Week, wk, ww -- Week
/// Hour, hh -- Hour
/// Minute, mi, n -- minute
/// Second, ss, s -- seconds
/// Millisecond, MS-millisecond
/// </Param>
/// <Param name = "beginDate" type = "DateTime">
/// Use it to compare my dates
/// </Param>
/// <Returns type = "int">
/// Return the absolute value of the date difference.
/// </Returns>
Datepart = datepart. toLowerCase ();
Var yearDiff = Math. abs (this. getFullYear ()-beginDate. getFullYear ());
Switch (datepart ){
Case "year ":
Case "yy ":
Case "yyyy ":
Return yearDiff;
Case "quarter ":
Case "qq ":
Case "q ":
Var qDiff = 0;
Switch (yearDiff ){
Case 0:
QDiff = Math. abs (this. getSeason ()-beginDate. getSeason ());
Break;
Case 1:
QDiff = (this. getSeason ()-new Date (this. getFullYear (), 0, 1). getSeason () +
(New Date (beginDate. getFullYear (), 11, 31). getSeason ()-
BeginDate. getSeason () + 1;
Break;
Default:
QDiff = (this. getSeason ()-new Date (this. getFullYear (), 0, 1). getSeason () +
(New Date (beginDate. getFullYear (), 11, 31). getSeason ()-
BeginDate. getSeason () + 1 + (yearDiff-1) * 4;
Break;
}
Return qDiff;
Case "month ":
Case "mm ":
Case "m ":
Var monthDiff = 0;
Switch (yearDiff ){
Case 0:
MonthDiff = Math. abs (this. getMonth ()-beginDate. getMonth ());
Break;
Case 1:
MonthDiff = (this. getMonth ()-new Date (this. getFullYear (), 0, 1). getMonth () +
(New Date (beginDate. getFullYear (), 11, 31). getMonth ()-
BeginDate. getMonth () + 1;
Break;
Default:
MonthDiff = (this. getMonth ()-new Date (this. getFullYear (), 0, 1). getMonth () +
(New Date (beginDate. getFullYear (), 11, 31). getMonth ()-
BeginDate. getMonth () + 1 + (yearDiff-1) * 12;
Break;
}
Return monthDiff;
Case "dayofyear ":
Case "dy ":
Case "y ":
Case "day ":
Case "dd ":
Case "d ":
Return Math. abs (this. setHours (0, 0, 0, 0)-beginDate. setHours (0, 0, 0, 0)/1000/60/60/24 );
Case "week ":
Case "wk ":
Case "ww ":
Var weekDiff = 0;
Switch (yearDiff ){
Case 0:
WeekDiff = Math. abs (this. getWeek ()-beginDate. getWeek ());
Break;
Case 1:
WeekDiff = (this. getWeek ()-new Date (this. getFullYear (), 0, 1). getWeek () +
(New Date (beginDate. getFullYear (), 11, 31). getWeek ()-
BeginDate. getWeek () + 1;
Break;
Default:

WeekDiff = (this. getWeek ()-new Date (this. getFullYear (), 0, 1). getWeek () +
(New Date (beginDate. getFullYear (), 11, 31). getWeek ()-
BeginDate. getWeek () + 1;
Var thisYear = this. getFullYear ();
For (var I = 1; I <yearDiff; I ++ ){
WeekDiff + = new Date (thisYear-I, 0, 1). getWeeksOfYear ();
}
Break;
}
Return weekDiff;
Case "hour ":
Case "hh ":
Return Math. abs (this-beginDate)/1000/60/60 );
Case "minute ":
Case "mi ":
Case "n ":
Return Math. abs (this-beginDate)/1000/60 );
Case "second ":
Case "ss ":
Case "s ":
Return Math. abs (this-beginDate)/1000 );
Case "millisecond ":
Case "ms ":
Return Math. abs (this-beginDate );
}
}
Date. prototype. getFirstWeekDays = function (){
/// <Summary>
/// Obtain the number of days in the first week of the year of the current date
/// </Summary>
Return (7-new Date (this. getFullYear (), 0, 1 ). getDay (); // the month in JS also starts from 0, and 0 indicates January, and so on.
}
Date. prototype. getLastWeekDays = function (year ){
/// <Summary>
/// Obtain the number of days of the last week in the year of the current date
/// </Summary>
Return (new Date (this. getFullYear (), 11, 31 ). getDay () + 1); // the month in JS also starts from 0. 0 indicates January, and so on.
}
Date. prototype. getWeeksOfYear = function (){
/// <Summary>
/// Obtain the week number Of The Year of the current date
/// </Summary>
Return (Math. ceil (new Date (this. getFullYear (), 11, 31, 23, 59, 59 )-
New Date (this. getFullYear (), 0, 1)/1000/60/60/24 )-
This. getFirstWeekDays ()-this. getLastWeekDays ()/7 + 2;
}
Date. prototype. getSeason = function (){
/// <Summary>
/// Obtain the quarter of the year where the current date is located. Returns a quarter integer.
/// </Summary>
Var month = this. getMonth ();
Switch (month ){
Case 0:
Case 1:
Case 2:
Return 1;
Case 3:
Case 4:
Case 5:
Return 2;
Case 6:
Case 7:
Case 8:
Return 3;
Default:
Return 4;
}
}
Date. prototype. getWeek = function (){
/// <Summary>
/// Obtain the week number of the year for the current date. Returns an integer.
/// </Summary>
Var firstDate = new Date (this. getFullYear (), 0, 1 );
Var firstWeekDays = this. getFirstWeekDays ();
Var secondWeekFirstDate = firstDate. add ("dd", firstWeekDays, true );
Var lastDate = new Date (this. getFullYear (), 11, 31 );
Var lastWeekDays = this. getLastWeekDays ();
If (this. dateDiff ("day", firstDate) <firstWeekDays ){
Return 1;
}
Else if (this. dateDiff ("day", lastDate) <lastWeekDays ){
Return this. getWeeksOfYear ();
}
Else {
Return Math. ceil (this-secondWeekFirstDate)/1000/60/60/24/7) + 1;
}
}