Addition and subtraction of dates in js

Addition and subtraction of dates in js

JavaScript code example for date addition and subtraction. Because JavaScript does not have the AddDays method similar to C #, you need to write a function to implement date addition and subtraction.

Today, let's make a summary of the date addition and subtraction in JS. There are two steps in total.

Step 1: Introduce date. format. js. The function of this JS is to convert the date to the specified format. The Code is as follows:

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Var dateFormat = function (){ Var token =/d {1, 4} | m {1, 4} | yy (? : Yy )? | ([HhMsTt]) \ 1? | [Losz] | "[^"] * "| '[^'] * '/g, Timezone =/\ B (? : [PMCEA] [SDP] T | (? : Pacific | Mountain | Central | Eastern | Atlanta )(? : Standard | Daylight | Prevailing) Time | (? : GMT | UTC )(? : [-+] \ D {4 })?) \ B/g, TimezoneClip =/[^-+ \ dA-Z]/g, Pad = function (val, len ){ Val = String (val ); Len = len | 2; While (val. length <len) val = "0" + val; Return val; };   // Regexes and supporting functions are cached through closure Return function (date, mask, utc ){ Var dF = dateFormat;   // You can't provide utc if you skip other args (use the "UTC:" mask prefix) If (arguments. length = 1 & Object. prototype. toString. call (date) = "[object String]" &! /\ D/. test (date )){ Mask = date; Date = undefined; }   // Passing date through Date applies Date. parse, if necessary Date = date? New Date (date): new Date; If (isNaN (date) throw SyntaxError ("invalid date ");   Mask = String (dF. masks [mask] | mask | dF. masks ["default"]);   // Allow setting the utc argument via the mask If (mask. slice (0, 4) = "UTC :"){ Mask = mask. slice (4 ); Utc = true; }   Var _ = utc? "GetUTC": "get ", D = date [_ + "Date"] (), D = date [_ + "Day"] (), M = date [_ + "Month"] (), Y = date [_ + "FullYear"] (), H = date [_ + "Hours"] (), M = date [_ + "Minutes"] (), S = date [_ + "Seconds"] (), L = date [_ + "Milliseconds"] (), O = utc? 0: date. getTimezoneOffset (), Flags = { D: d, Dd: pad (d ), Ddd: dF. i18n. dayNames [D], Dddd: dF. i18n. dayNames [D + 7], M: m + 1, Mm: pad (m + 1 ), Mmm: dF. i18n. monthNames [m], Mmmm: dF. i18n. monthNames [m + 12], Yy: String (y). slice (2 ), Yyyy: y, H: H % 12 | 12, Hh: pad (H % 12 | 12 ), H: H, HH: pad (H ), M: M, MM: pad (M ), S: s, Ss: pad (s ), L: pad (L, 3 ), L: pad (L> 99? Math. round (L/10): L ), T: H <12? "A": "p ", Tt: H <12? "Am": "pm ", T: H <12? "A": "P ", TT: H <12? "AM": "PM ", Z: utc? "UTC": (String (date). match (timezone) | [""]). pop (). replace (timezoneClip ,""), O: (o> 0? "-": "+") + Pad (Math. floor (Math. abs (o)/60) * 100 + Math. abs (o) % 60, 4 ), S: ["th", "st", "nd", "rd"] [d % 10> 3? 0: (d % 100-d % 10! = 10) * d % 10] };   Return mask. replace (token, function ($0 ){ Return $0 in flags? Flags [$0]: $0. slice (1, $0. length-1 ); }); }; }();   // Some common format strings DateFormat. masks = { "Default": "ddd mmm dd yyyy HH: MM: ss ", Expiry date: "m/d/yy ", MediumDate: "mmm d, yyyy ", LongDate: "mmmm d, yyyy ", FullDate: "dddd, mmmm d, yyyy ", Processing time: "h: mm tt ", MediumTime: "h: MM: ss TT ", LongTime: "h: MM: ss tt z ", IsoDate: "yyyy-mm-dd ", IsoTime: "HH: MM: ss ", IsoDateTime: "yyyy-mm-dd't'hh: MM: ss ", IsoUtcDateTime: "UTC: yyyy-mm-dd't'hh: MM: ss 'Z '" };   // Internationalization strings DateFormat. i18n = { DayNames :[ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat ", "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" ], MonthNames :[ "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct ", "Nov", "Dec ", "January", "February", "March", "maid", "May", "June", "July", "August", "September", "October ", "November", "December" ] };   // For convenience... Date. prototype. format = function (mask, utc ){ Return dateFormat (this, mask, utc ); };

Step 2: Convert the time to milliseconds for addition and subtraction calculation, and then convert the above js to the specified date.

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Var nowDate = new Date (); // Addition operation Var ysDate = new Date (nowDate. getTime ()-30x24*60*60*1000). format ('yyyy-mm-dd '); // Subtraction Var yeDate = new Date (nowDate. getTime ()-24*60*60*1000). format ('yyyy-m-d ');

Through the above two steps, the date addition and subtraction in JS is implemented. How is it easy! Try it!

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