functions/date.php

   1 <?php
   2
   3 /**
   4  * date.php
   5  *
   6  * Takes a date and parses it into a usable format.  The form that a
   7  * date SHOULD arrive in is:
   8  *       <Tue,> 29 Jun 1999 09:52:11 -0500 (EDT)
   9  * (as specified in RFC 822) -- 'Tue' is optional
  10  *
  11  * @copyright &copy; 1999-2006 The SquirrelMail Project Team
  12  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
  13  * @version $Id$
  14  * @package squirrelmail
  15  * @subpackage date
  16  */
  17
  18 /**
  19  * dependency information
  20  * - none
  21  */
  22
  23 /**
  24  * Corrects a time stamp to be the local time.
  25  *
  26  * @param int stamp the timestamp to adjust
  27  * @param string tzc the timezone correction
  28  * @return int the corrected timestamp
  29  */
  30 function getGMTSeconds($stamp, $tzc) {
  31     /* date couldn't be parsed */
  32     if ($stamp == -1) {
  33         return -1;
  34     }
  35     /* timezone correction, expressed as `shhmm' */
  36     switch($tzc)
  37     {
  38         case 'Pacific':
  39         case 'PST':
  40             $tzc = '-0800';
  41             break;
  42         case 'Mountain':
  43         case 'MST':
  44         case 'PDT':
  45             $tzc = '-0700';
  46             break;
  47         case 'Central':
  48         case 'CST':
  49         case 'MDT':
  50             $tzc = '-0600';
  51             break;
  52         case 'Eastern':
  53         case 'EST':
  54         case 'CDT':
  55             $tzc = '-0500';
  56             break;
  57         case 'EDT':
  58             $tzc = '-0400';
  59             break;
  60         case 'GMT':
  61             $tzc = '+0000';
  62             break;
  63         case 'BST':
  64         case 'MET':
  65         case 'CET':
  66             $tzc = '+0100';
  67             break;
  68         case 'EET':
  69         case 'IST':
  70         case 'MET DST':
  71         case 'METDST':
  72             $tzc = '+0200';
  73             break;
  74         case 'HKT':
  75             $tzc = '+0800';
  76             break;
  77         case 'JST':
  78         case 'KST':
  79             $tzc = '+0900';
  80             break;
  81     }
  82     $neg = false;
  83     if (substr($tzc, 0, 1) == '-') {
  84         $neg = true;
  85     } else if (substr($tzc, 0, 1) != '+') {
  86         $tzc = '+'.$tzc;
  87     }
  88     $hh = substr($tzc,1,2);
  89     $mm = substr($tzc,3,2);
  90     $iTzc = ($hh * 60 + $mm) * 60;
  91     if ($neg) $iTzc = -1 * (int) $iTzc;
  92     /* stamp in gmt */
  93     $stamp -= $iTzc;
  94     /* now find what the server is at */
  95     $current = date('Z', time());
  96     /* stamp in local timezone */
  97     $stamp += $current;
  98
  99     return $stamp;
 100 }
 101
 102 /**
 103  * Returns the (localized) string for a given day number.
 104  * Switch system has been intentionaly chosen for the
 105  * internationalization of month and day names. The reason
 106  * is to make sure that _("") strings will go into the
 107  * main po.
 108  *
 109  * @param int day_number the day number
 110  * @return string the day in human readable form
 111  */
 112 function getDayName( $day_number ) {
 113
 114     switch( $day_number ) {
 115     case 0:
 116         $ret = _("Sunday");
 117         break;
 118     case 1:
 119         $ret = _("Monday");
 120         break;
 121     case 2:
 122         $ret = _("Tuesday");
 123         break;
 124     case 3:
 125         $ret = _("Wednesday");
 126         break;
 127     case 4:
 128         $ret = _("Thursday");
 129         break;
 130     case 5:
 131         $ret = _("Friday");
 132         break;
 133     case 6:
 134         $ret = _("Saturday");
 135         break;
 136     default:
 137         $ret = '';
 138     }
 139     return( $ret );
 140 }
 141
 142 /**
 143  * Like getDayName, but returns the short form
 144  * @param int day_number the day number
 145  * @return string the day in short human readable form
 146  */
 147 function getDayAbrv( $day_number ) {
 148
 149     switch( $day_number ) {
 150     case 0:
 151         $ret = _("Sun");
 152         break;
 153     case 1:
 154         $ret = _("Mon");
 155         break;
 156     case 2:
 157         $ret = _("Tue");
 158         break;
 159     case 3:
 160         $ret = _("Wed");
 161         break;
 162     case 4:
 163         $ret = _("Thu");
 164         break;
 165     case 5:
 166         $ret = _("Fri");
 167         break;
 168     case 6:
 169         $ret = _("Sat");
 170         break;
 171     default:
 172         $ret = '';
 173     }
 174     return( $ret );
 175 }
 176
 177
 178 /**
 179  * Returns the (localized) string for a given month number.
 180  *
 181  * @param string month_number the month number (01..12)
 182  * @return string the month name in human readable form
 183  */
 184 function getMonthName( $month_number ) {
 185     switch( $month_number ) {
 186      case '01':
 187         $ret = _("January");
 188         break;
 189      case '02':
 190         $ret = _("February");
 191         break;
 192      case '03':
 193         $ret = _("March");
 194         break;
 195      case '04':
 196         $ret = _("April");
 197         break;
 198      case '05':
 199         $ret = _("May");
 200         break;
 201      case '06':
 202         $ret = _("June");
 203         break;
 204      case '07':
 205         $ret = _("July");
 206         break;
 207      case '08':
 208         $ret = _("August");
 209         break;
 210      case '09':
 211         $ret = _("September");
 212         break;
 213      case '10':
 214         $ret = _("October");
 215         break;
 216      case '11':
 217         $ret = _("November");
 218         break;
 219      case '12':
 220         $ret = _("December");
 221         break;
 222      default:
 223         $ret = '';
 224     }
 225     return( $ret );
 226 }
 227
 228 /**
 229  * Returns the (localized) string for a given month number,
 230  * short representation.
 231  *
 232  * @param string month_number the month number (01..12)
 233  * @return string the shortened month in human readable form
 234  */
 235 function getMonthAbrv( $month_number ) {
 236     switch( $month_number ) {
 237      case '01':
 238         $ret = _("Jan");
 239         break;
 240      case '02':
 241         $ret = _("Feb");
 242         break;
 243      case '03':
 244         $ret = _("Mar");
 245         break;
 246      case '04':
 247         $ret = _("Apr");
 248         break;
 249      case '05':
 250         $ret = _("Ma&#121;");
 251         break;
 252      case '06':
 253         $ret = _("Jun");
 254         break;
 255      case '07':
 256         $ret = _("Jul");
 257         break;
 258      case '08':
 259         $ret = _("Aug");
 260         break;
 261      case '09':
 262         $ret = _("Sep");
 263         break;
 264      case '10':
 265         $ret = _("Oct");
 266         break;
 267      case '11':
 268         $ret = _("Nov");
 269         break;
 270      case '12':
 271         $ret = _("Dec");
 272         break;
 273      default:
 274         $ret = '';
 275     }
 276     return( $ret );
 277 }
 278
 279 /**
 280  * Returns the localized representation of the date/time.
 281  *
 282  * @param string date_format The format for the date, like the input for the PHP date() function.
 283  * @param int stamp the timestamp to convert
 284  * @return string a full date representation
 285  */
 286 function date_intl( $date_format, $stamp ) {
 287     $ret = str_replace( array('D','F','l','M'), array('$1','$2','$3','$4'), $date_format );
 288     // to reduce the date calls we retrieve m and w in the same call
 289     $ret = date('w#m#'. $ret, $stamp );
 290     // extract day and month in order to replace later by intl day and month
 291     $aParts = explode('#',$ret);
 292     $ret = str_replace(array('$1','$4','$2','$3',), array(getDayAbrv($aParts[0]),
 293                                                           getMonthAbrv($aParts[1]),
 294                                                           getMonthName($aParts[1]),
 295                                                           getDayName($aParts[0])),
 296                                                           $aParts[2]);
 297     return( $ret );
 298 }
 299
 300 /**
 301  * This returns a date of the format "Wed, Oct 29, 2003 9:52 am",
 302  * or the same in 24H format (depending on the user's settings),
 303  * and taking localization into accout.
 304  *
 305  * @param int stamp the timestamp
 306  * @return string the long date string
 307  */
 308 function getLongDateString( $stamp ) {
 309
 310     global $hour_format;
 311
 312     if ($stamp == -1) {
 313         return '';
 314     }
 315
 316     if ( $hour_format == SMPREF_TIME_12HR ) {
 317         $date_format = _("D, F j, Y g:i a");
 318     } else {
 319         $date_format = _("D, F j, Y H:i");
 320     }
 321
 322     return( date_intl( $date_format, $stamp ) );
 323
 324 }
 325
 326 /**
 327  * Returns a short representation of the date,
 328  * taking timezones and localization into account.
 329  * Depending on user's settings, this string can be
 330  * of the form: "14:23" or "Jun 14, 2003" depending
 331  * on whether the stamp is "today" or not.
 332  *
 333  * @param int stamp the timestamp
 334  * @return string the date string
 335  */
 336 function getDateString( $stamp ) {
 337
 338     global $invert_time, $hour_format, $show_full_date;
 339
 340     if ( $stamp == -1 ) {
 341        return '';
 342     }
 343
 344     $now = time();
 345
 346     $dateZ = date('Z', $now );
 347
 348     // FIXME: isn't this obsolete and introduced as a terrible workaround
 349     // for bugs at other places which are fixed a long time ago?
 350     if ($invert_time) {
 351         $dateZ = - $dateZ;
 352     }
 353
 354     // calculate when it was midnight and when it will be,
 355     // in order to display dates differently if they're 'today'
 356     $midnight = $now - ($now % 86400) - $dateZ;
 357     // this is to correct if after calculations midnight is more than
 358     // one whole day away.
 359     if ($now - $midnight > 86400) {
 360         $midnight += 86400;
 361     }
 362     $nextmid = $midnight + 86400;
 363
 364     if (($show_full_date == 1) || ($nextmid < $stamp)) {
 365         $date_format = _("M j, Y");
 366     } else if ($midnight < $stamp) {
 367         /* Today */
 368         if ( $hour_format == SMPREF_TIME_12HR ) {
 369             $date_format = _("g:i a");
 370         } else {
 371             $date_format = _("H:i");
 372         }
 373     } else if ($midnight - 518400 < $stamp) {
 374         /* This week */
 375         if ( $hour_format == SMPREF_TIME_12HR ) {
 376             $date_format = _("D, g:i a");
 377         } else {
 378             $date_format = _("D, H:i");
 379         }
 380     } else {
 381         /* before this week */
 382         $date_format = _("M j, Y");
 383     }
 384
 385     return( date_intl( $date_format, $stamp ) );
 386 }
 387
 388 /**
 389  * Decodes a RFC 822 Date-header into a timestamp
 390  *
 391  * @param array dateParts the Date-header split by whitespace
 392  * @return int the timestamp calculated from the header
 393  */
 394 function getTimeStamp($dateParts) {
 395     /* $dateParts[0] == <day of week>   Mon, Tue, Wed
 396      * $dateParts[1] == <day of month>  23
 397      * $dateParts[2] == <month>         Jan, Feb, Mar
 398      * $dateParts[3] == <year>          1999
 399      * $dateParts[4] == <time>          18:54:23 (HH:MM:SS)
 400      * $dateParts[5] == <from GMT>      +0100
 401      * $dateParts[6] == <zone>          (EDT)
 402      *
 403      * NOTE:  In RFC 822, it states that <day of week> is optional.
 404      *        In that case, dateParts[0] would be the <day of month>
 405      *        and everything would be bumped up one.
 406      */
 407
 408     /*
 409      * Simply check to see if the first element in the dateParts
 410      * array is an integer or not.
 411      * Since the day of week is optional, this check is needed.
 412      */
 413      if (count($dateParts) <2) {
 414         return -1;
 415      } else if (count($dateParts) ==3) {
 416         if (substr_count($dateParts[0],'-') == 2 &&
 417             substr_count($dateParts[1],':') == 2) {
 418             //  dd-Month-yyyy 23:19:05 +0200
 419             //  redefine the date
 420             $aDate = explode('-',$dateParts[0]);
 421             $newDate = array($aDate[0],$aDate[1],$aDate[2],$dateParts[1],$dateParts[2]);
 422             $dateParts = $newDate;
 423         }
 424      }
 425
 426     /* remove day of week */
 427     if (!is_numeric(trim($dateParts[0]))) {
 428         $dataParts = array_shift($dateParts);
 429     }
 430     /* calculate timestamp separated from the zone and obs-zone */
 431     $stamp = strtotime(implode (' ', array_splice ($dateParts,0,4)));
 432     if (!isset($dateParts[0])) {
 433         $dateParts[0] = '+0000';
 434     }
 435
 436     if (!preg_match('/^[+-]{1}[0-9]{4}$/',$dateParts[0])) {
 437         /* zone in obs-zone format */
 438         if (preg_match('/\((.+)\)/',$dateParts[0],$regs)) {
 439             $obs_zone = $regs[1];
 440         } else {
 441             $obs_zone = $dateParts[0];
 442         }
 443         return getGMTSeconds($stamp, $obs_zone);
 444     } else {
 445         return getGMTSeconds($stamp, $dateParts[0]);
 446     }
 447 }