js/date.js

   1 // ===================================================================
   2 // Author: Matt Kruse <matt@mattkruse.com>
   3 // WWW: http://www.mattkruse.com/
   4 //
   5 // NOTICE: You may use this code for any purpose, commercial or
   6 // private, without any further permission from the author. You may
   7 // remove this notice from your final code if you wish, however it is
   8 // appreciated by the author if at least my web site address is kept.
   9 //
  10 // You may *NOT* re-distribute this code in any way except through its
  11 // use. That means, you can include it in your product, or your web
  12 // site, or any other form where the code is actually being used. You
  13 // may not put the plain javascript up on your site for download or
  14 // include it in your javascript libraries for download.
  15 // If you wish to share this code with others, please just point them
  16 // to the URL instead.
  17 // Please DO NOT link directly to my .js files from your site. Copy
  18 // the files to your server and use them there. Thank you.
  19 // ===================================================================
  20
  21 // HISTORY
  22 // ------------------------------------------------------------------
  23 // May 17, 2003: Fixed bug in parseDate() for dates <1970
  24 // March 11, 2003: Added parseDate() function
  25 // March 11, 2003: Added "NNN" formatting option. Doesn't match up
  26 //                 perfectly with SimpleDateFormat formats, but
  27 //                 backwards-compatability was required.
  28
  29 // ------------------------------------------------------------------
  30 // These functions use the same 'format' strings as the
  31 // java.text.SimpleDateFormat class, with minor exceptions.
  32 // The format string consists of the following abbreviations:
  33 //
  34 // Field        | Full Form          | Short Form
  35 // -------------+--------------------+-----------------------
  36 // Year         | yyyy (4 digits)    | yy (2 digits), y (2 or 4 digits)
  37 // Month        | MMM (name or abbr.)| MM (2 digits), M (1 or 2 digits)
  38 //              | NNN (abbr.)        |
  39 // Day of Month | dd (2 digits)      | d (1 or 2 digits)
  40 // Day of Week  | EE (name)          | E (abbr)
  41 // Hour (1-12)  | hh (2 digits)      | h (1 or 2 digits)
  42 // Hour (0-23)  | HH (2 digits)      | H (1 or 2 digits)
  43 // Hour (0-11)  | KK (2 digits)      | K (1 or 2 digits)
  44 // Hour (1-24)  | kk (2 digits)      | k (1 or 2 digits)
  45 // Minute       | mm (2 digits)      | m (1 or 2 digits)
  46 // Second       | ss (2 digits)      | s (1 or 2 digits)
  47 // AM/PM        | a                  |
  48 //
  49 // NOTE THE DIFFERENCE BETWEEN MM and mm! Month=MM, not mm!
  50 // Examples:
  51 //  "MMM d, y" matches: January 01, 2000
  52 //                      Dec 1, 1900
  53 //                      Nov 20, 00
  54 //  "M/d/yy"   matches: 01/20/00
  55 //                      9/2/00
  56 //  "MMM dd, yyyy hh:mm:ssa" matches: "January 01, 2000 12:30:45AM"
  57 // ------------------------------------------------------------------
  58
  59 var MONTH_NAMES=new Array('January','February','March','April','May','June','July','August','September','October','November','December','Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
  60 var DAY_NAMES=new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sun','Mon','Tue','Wed','Thu','Fri','Sat');
  61 function LZ(x) {return(x<0||x>9?"":"0")+x}
  62
  63 // ------------------------------------------------------------------
  64 // isDate ( date_string, format_string )
  65 // Returns true if date string matches format of format string and
  66 // is a valid date. Else returns false.
  67 // It is recommended that you trim whitespace around the value before
  68 // passing it to this function, as whitespace is NOT ignored!
  69 // ------------------------------------------------------------------
  70 function isDate(val,format) {
  71         var date=getDateFromFormat(val,format);
  72         if (date==0) { return false; }
  73         return true;
  74         }
  75
  76 // -------------------------------------------------------------------
  77 // compareDates(date1,date1format,date2,date2format)
  78 //   Compare two date strings to see which is greater.
  79 //   Returns:
  80 //   1 if date1 is greater than date2
  81 //   0 if date2 is greater than date1 of if they are the same
  82 //  -1 if either of the dates is in an invalid format
  83 // -------------------------------------------------------------------
  84 function compareDates(date1,dateformat1,date2,dateformat2) {
  85         var d1=getDateFromFormat(date1,dateformat1);
  86         var d2=getDateFromFormat(date2,dateformat2);
  87         if (d1==0 || d2==0) {
  88                 return -1;
  89                 }
  90         else if (d1 > d2) {
  91                 return 1;
  92                 }
  93         return 0;
  94         }
  95
  96 // ------------------------------------------------------------------
  97 // formatDate (date_object, format)
  98 // Returns a date in the output format specified.
  99 // The format string uses the same abbreviations as in getDateFromFormat()
 100 // ------------------------------------------------------------------
 101 function formatDate(date,format) {
 102         format=format+"";
 103         var result="";
 104         var i_format=0;
 105         var c="";
 106         var token="";
 107         var y=date.getYear()+"";
 108         var M=date.getMonth()+1;
 109         var d=date.getDate();
 110         var E=date.getDay();
 111         var H=date.getHours();
 112         var m=date.getMinutes();
 113         var s=date.getSeconds();
 114         var yyyy,yy,MMM,MM,dd,hh,h,mm,ss,ampm,HH,H,KK,K,kk,k;
 115         // Convert real date parts into formatted versions
 116         var value=new Object();
 117         if (y.length < 4) {y=""+(y-0+1900);}
 118         value["y"]=""+y;
 119         value["yyyy"]=y;
 120         value["yy"]=y.substring(2,4);
 121         value["M"]=M;
 122         value["MM"]=LZ(M);
 123         value["MMM"]=MONTH_NAMES[M-1];
 124         value["NNN"]=MONTH_NAMES[M+11];
 125         value["d"]=d;
 126         value["dd"]=LZ(d);
 127         value["E"]=DAY_NAMES[E+7];
 128         value["EE"]=DAY_NAMES[E];
 129         value["H"]=H;
 130         value["HH"]=LZ(H);
 131         if (H==0){value["h"]=12;}
 132         else if (H>12){value["h"]=H-12;}
 133         else {value["h"]=H;}
 134         value["hh"]=LZ(value["h"]);
 135         if (H>11){value["K"]=H-12;} else {value["K"]=H;}
 136         value["k"]=H+1;
 137         value["KK"]=LZ(value["K"]);
 138         value["kk"]=LZ(value["k"]);
 139         if (H > 11) { value["a"]="PM"; }
 140         else { value["a"]="AM"; }
 141         value["m"]=m;
 142         value["mm"]=LZ(m);
 143         value["s"]=s;
 144         value["ss"]=LZ(s);
 145         while (i_format < format.length) {
 146                 c=format.charAt(i_format);
 147                 token="";
 148                 while ((format.charAt(i_format)==c) && (i_format < format.length)) {
 149                         token += format.charAt(i_format++);
 150                         }
 151                 if (value[token] != null) { result=result + value[token]; }
 152                 else { result=result + token; }
 153                 }
 154         return result;
 155         }
 156
 157 // ------------------------------------------------------------------
 158 // Utility functions for parsing in getDateFromFormat()
 159 // ------------------------------------------------------------------
 160 function _isInteger(val) {
 161         var digits="1234567890";
 162         for (var i=0; i < val.length; i++) {
 163                 if (digits.indexOf(val.charAt(i))==-1) { return false; }
 164                 }
 165         return true;
 166         }
 167 function _getInt(str,i,minlength,maxlength) {
 168         for (var x=maxlength; x>=minlength; x--) {
 169                 var token=str.substring(i,i+x);
 170                 if (token.length < minlength) { return null; }
 171                 if (_isInteger(token)) { return token; }
 172                 }
 173         return null;
 174         }
 175
 176 // ------------------------------------------------------------------
 177 // getDateFromFormat( date_string , format_string )
 178 //
 179 // This function takes a date string and a format string. It matches
 180 // If the date string matches the format string, it returns the
 181 // getTime() of the date. If it does not match, it returns 0.
 182 // ------------------------------------------------------------------
 183 function getDateFromFormat(val,format) {
 184         val=val+"";
 185         format=format+"";
 186         var i_val=0;
 187         var i_format=0;
 188         var c="";
 189         var token="";
 190         var token2="";
 191         var x,y;
 192         var now=new Date();
 193         var year=now.getYear();
 194         var month=now.getMonth()+1;
 195         var date=1;
 196         var hh=now.getHours();
 197         var mm=now.getMinutes();
 198         var ss=now.getSeconds();
 199         var ampm="";
 200
 201         while (i_format < format.length) {
 202                 // Get next token from format string
 203                 c=format.charAt(i_format);
 204                 token="";
 205                 while ((format.charAt(i_format)==c) && (i_format < format.length)) {
 206                         token += format.charAt(i_format++);
 207                         }
 208                 // Extract contents of value based on format token
 209                 if (token=="yyyy" || token=="yy" || token=="y") {
 210                         if (token=="yyyy") { x=4;y=4; }
 211                         if (token=="yy")   { x=2;y=2; }
 212                         if (token=="y")    { x=2;y=4; }
 213                         year=_getInt(val,i_val,x,y);
 214                         if (year==null) { return 0; }
 215                         i_val += year.length;
 216                         if (year.length==2) {
 217                                 if (year > 70) { year=1900+(year-0); }
 218                                 else { year=2000+(year-0); }
 219                                 }
 220                         }
 221                 else if (token=="MMM"||token=="NNN"){
 222                         month=0;
 223                         for (var i=0; i<MONTH_NAMES.length; i++) {
 224                                 var month_name=MONTH_NAMES[i];
 225                                 if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
 226                                         if (token=="MMM"||(token=="NNN"&&i>11)) {
 227                                                 month=i+1;
 228                                                 if (month>12) { month -= 12; }
 229                                                 i_val += month_name.length;
 230                                                 break;
 231                                                 }
 232                                         }
 233                                 }
 234                         if ((month < 1)||(month>12)){return 0;}
 235                         }
 236                 else if (token=="EE"||token=="E"){
 237                         for (var i=0; i<DAY_NAMES.length; i++) {
 238                                 var day_name=DAY_NAMES[i];
 239                                 if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
 240                                         i_val += day_name.length;
 241                                         break;
 242                                         }
 243                                 }
 244                         }
 245                 else if (token=="MM"||token=="M") {
 246                         month=_getInt(val,i_val,token.length,2);
 247                         if(month==null||(month<1)||(month>12)){return 0;}
 248                         i_val+=month.length;}
 249                 else if (token=="dd"||token=="d") {
 250                         date=_getInt(val,i_val,token.length,2);
 251                         if(date==null||(date<1)||(date>31)){return 0;}
 252                         i_val+=date.length;}
 253                 else if (token=="hh"||token=="h") {
 254                         hh=_getInt(val,i_val,token.length,2);
 255                         if(hh==null||(hh<1)||(hh>12)){return 0;}
 256                         i_val+=hh.length;}
 257                 else if (token=="HH"||token=="H") {
 258                         hh=_getInt(val,i_val,token.length,2);
 259                         if(hh==null||(hh<0)||(hh>23)){return 0;}
 260                         i_val+=hh.length;}
 261                 else if (token=="KK"||token=="K") {
 262                         hh=_getInt(val,i_val,token.length,2);
 263                         if(hh==null||(hh<0)||(hh>11)){return 0;}
 264                         i_val+=hh.length;}
 265                 else if (token=="kk"||token=="k") {
 266                         hh=_getInt(val,i_val,token.length,2);
 267                         if(hh==null||(hh<1)||(hh>24)){return 0;}
 268                         i_val+=hh.length;hh--;}
 269                 else if (token=="mm"||token=="m") {
 270                         mm=_getInt(val,i_val,token.length,2);
 271                         if(mm==null||(mm<0)||(mm>59)){return 0;}
 272                         i_val+=mm.length;}
 273                 else if (token=="ss"||token=="s") {
 274                         ss=_getInt(val,i_val,token.length,2);
 275                         if(ss==null||(ss<0)||(ss>59)){return 0;}
 276                         i_val+=ss.length;}
 277                 else if (token=="a") {
 278                         if (val.substring(i_val,i_val+2).toLowerCase()=="am") {ampm="AM";}
 279                         else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {ampm="PM";}
 280                         else {return 0;}
 281                         i_val+=2;}
 282                 else {
 283                         if (val.substring(i_val,i_val+token.length)!=token) {return 0;}
 284                         else {i_val+=token.length;}
 285                         }
 286                 }
 287         // If there are any trailing characters left in the value, it doesn't match
 288         if (i_val != val.length) { return 0; }
 289         // Is date valid for month?
 290         if (month==2) {
 291                 // Check for leap year
 292                 if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
 293                         if (date > 29){ return 0; }
 294                         }
 295                 else { if (date > 28) { return 0; } }
 296                 }
 297         if ((month==4)||(month==6)||(month==9)||(month==11)) {
 298                 if (date > 30) { return 0; }
 299                 }
 300         // Correct hours value
 301         if (hh<12 && ampm=="PM") { hh=hh-0+12; }
 302         else if (hh>11 && ampm=="AM") { hh-=12; }
 303         var newdate=new Date(year,month-1,date,hh,mm,ss);
 304         return newdate.getTime();
 305         }
 306
 307 // ------------------------------------------------------------------
 308 // parseDate( date_string [, prefer_euro_format] )
 309 //
 310 // This function takes a date string and tries to match it to a
 311 // number of possible date formats to get the value. It will try to
 312 // match against the following international formats, in this order:
 313 // y-M-d   MMM d, y   MMM d,y   y-MMM-d   d-MMM-y  MMM d
 314 // M/d/y   M-d-y      M.d.y     MMM-d     M/d      M-d
 315 // d/M/y   d-M-y      d.M.y     d-MMM     d/M      d-M
 316 // A second argument may be passed to instruct the method to search
 317 // for formats like d/M/y (european format) before M/d/y (American).
 318 // Returns a Date object or null if no patterns match.
 319 // ------------------------------------------------------------------
 320 function parseDate(val) {
 321         var preferEuro=(arguments.length==2)?arguments[1]:false;
 322         generalFormats=new Array('y-M-d','MMM d, y','MMM d,y','y-MMM-d','d-MMM-y','MMM d');
 323         monthFirst=new Array('M/d/y','M-d-y','M.d.y','MMM-d','M/d','M-d');
 324         dateFirst =new Array('d/M/y','d-M-y','d.M.y','d-MMM','d/M','d-M');
 325         var checkList=new Array('generalFormats',preferEuro?'dateFirst':'monthFirst',preferEuro?'monthFirst':'dateFirst');
 326         var d=null;
 327         for (var i=0; i<checkList.length; i++) {
 328                 var l=window[checkList[i]];
 329                 for (var j=0; j<l.length; j++) {
 330                         d=getDateFromFormat(val,l[j]);
 331                         if (d!=0) { return new Date(d); }
 332                         }
 333                 }
 334         return null;
 335         }