ID: 20382 Updated by: [EMAIL PROTECTED] Reported By: nickj-phpbugs at nickj dot org -Status: Verified +Status: Closed Bug Type: Date/time related Operating System: * PHP Version: 4CVS, 5CVS Assigned To: hholzgra New Comment:
This bug has been fixed in CVS. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. Thank you for the report, and for helping us make PHP better. Previous Comments: ------------------------------------------------------------------------ [2003-04-06 18:47:03] scottmacvicar at ntlworld dot com This is a DST problem by the looks of it. The specific dates mentioned are when DST takes effect which is the last sunday in March. ------------------------------------------------------------------------ [2002-11-12 19:46:28] nickj-phpbugs at nickj dot org OK, I decided that was needed was some kind of automated testing, so I wrote it: ============================================ #!/root/php4-200211122230 -q <?php // report any errors at all error_reporting (E_ALL); // pass a date, supply a strtotime modifier, and get a date back function getDateWithModifier($date, $modifier) { list ($year, $month, $day) = explode ("-",$date); $starting_timestamp = mktime (1,1,1,$month,$day,$year); $timestamp_with_modifier = strtotime ($modifier, $starting_timestamp); return date("Y-n-j", $timestamp_with_modifier); } /* ** @desc: for the specified date, will find the date for the desired day of the ** week that is also in the same week. Does NOT use 'strtotime' */ function getDayOfTheWeekFromDate($date, $desired_day_of_week) { // weekdays - note special case for sundays (7, not 0), so as to treat as end of week, not start $weekdays = array ("Sunday" => 7, "Monday" => 1, "Tuesday" => 2, "Wednesday" => 3, "Thursday" => 4, "Friday" => 5, "Saturday" => 6); // convert into a number $desired_day_of_week_number = $weekdays[$desired_day_of_week]; // see what day we have currently list ($year, $month, $day) = explode ("-",$date); $date_day_of_week = date("w", mktime (17,17,17,$month,$day,$year)); $new_day = $day+(($desired_day_of_week_number-$date_day_of_week)+7) % 7; return date("Y-n-j", mktime (17,17,17,$month,$new_day,$year)); } // run an automated test to compare the output of these two functions, and complain if they differ for ($i=1; $i<1000; $i++) { $date = date("Y-n-j", mktime (17,17,17,1,$i,1999)); $strtotime_date = getDateWithModifier($date, "Monday"); $other_date = getDayOfTheWeekFromDate($date, "Monday"); if ($strtotime_date != $other_date) { print "Discrepancy for $date - results were $strtotime_date vs $other_date\n"; } } print "PHP version: " . phpversion(). "<br>\n"; ?> ============================================ Here's the output that I get: ============================================ [EMAIL PROTECTED] tmp]# ./automated-date-test.php Discrepancy for 1999-3-23 - results were 1999-3-28 vs 1999-3-29 Discrepancy for 1999-3-24 - results were 1999-3-28 vs 1999-3-29 Discrepancy for 1999-3-25 - results were 1999-3-28 vs 1999-3-29 Discrepancy for 1999-3-26 - results were 1999-3-28 vs 1999-3-29 Discrepancy for 1999-3-27 - results were 1999-3-28 vs 1999-3-29 Discrepancy for 1999-3-28 - results were 1999-3-28 vs 1999-3-29 Discrepancy for 2000-3-21 - results were 2000-3-26 vs 2000-3-27 Discrepancy for 2000-3-22 - results were 2000-3-26 vs 2000-3-27 Discrepancy for 2000-3-23 - results were 2000-3-26 vs 2000-3-27 Discrepancy for 2000-3-24 - results were 2000-3-26 vs 2000-3-27 Discrepancy for 2000-3-25 - results were 2000-3-26 vs 2000-3-27 Discrepancy for 2000-3-26 - results were 2000-3-26 vs 2000-3-27 Discrepancy for 2001-3-20 - results were 2001-3-25 vs 2001-3-26 Discrepancy for 2001-3-21 - results were 2001-3-25 vs 2001-3-26 Discrepancy for 2001-3-22 - results were 2001-3-25 vs 2001-3-26 Discrepancy for 2001-3-23 - results were 2001-3-25 vs 2001-3-26 Discrepancy for 2001-3-24 - results were 2001-3-25 vs 2001-3-26 Discrepancy for 2001-3-25 - results were 2001-3-25 vs 2001-3-26 PHP version: 4.3.0-dev<br> [EMAIL PROTECTED] tmp]# ============================================ In other words, the result for these 6 days of the year consistently appears to be wrong. (I suppose I should be glad that the very first date I choose to test this function with just by fluke happened to be one of those 6 days, as opposed to causing mysterious problems later!) Does anyone else get any results that appear incorrect on running this script? ------------------------------------------------------------------------ [2002-11-12 02:11:16] nickj-phpbugs at nickj dot org Strtotime() appears to produce incorrect output under some circumstances - specifically when wanting the date of a particular day of the week day of the week from a given starting date. For example, using 2001-3-20 as a starting point, we want the date for the next Monday. The correct answer is the 26th, but the result produced is the 25th (a Sunday). The correct result is given sometimes, so this appears to depend on the input. A sample script to illustrate: ======================================================= #!/root/php-4.2.3 -q <?php // report any errors at all error_reporting (E_ALL); // pass a date, supply a strtotime modifier, and get a date back function getDateWithModifier($date, $modifier) { list ($year, $month, $day) = explode ("-",$date); $starting_timestamp = mktime (10,10,10,$month,$day,$year); $timestamp_with_modifier = strtotime ($modifier, $starting_timestamp); return date("Y-n-j", $timestamp_with_modifier); } print "<hr>\n"; print "from 2001-3-17, goto monday: " . getDateWithModifier("2001-3-17", "Monday") . "; should be 2001-3-19.<br>\n"; print "from 2001-3-18, goto monday: " . getDateWithModifier("2001-3-18", "Monday") . "; should be 2001-3-19.<br>\n"; print "from 2001-3-19, goto monday: " . getDateWithModifier("2001-3-19", "Monday") . "; should be 2001-3-19.<br>\n"; print "from 2001-3-20, goto monday: " . getDateWithModifier("2001-3-20", "Monday") . "; should be 2001-3-26 ###.<br>\n"; print "from 2001-3-21, goto monday: " . getDateWithModifier("2001-3-21", "Monday") . "; should be 2001-3-26 ###.<br>\n"; print "from 2001-3-22, goto monday: " . getDateWithModifier("2001-3-22", "Monday") . "; should be 2001-3-26 ###.<br>\n"; print "from 2001-3-23, goto monday: " . getDateWithModifier("2001-3-23", "Monday") . "; should be 2001-3-26 ###.<br>\n"; print "from 2001-3-24, goto monday: " . getDateWithModifier("2001-3-24", "Monday") . "; should be 2001-3-26 ###.<br>\n"; print "from 2001-3-25, goto monday: " . getDateWithModifier("2001-3-25", "Monday") . "; should be 2001-3-26 ###.<br>\n"; print "from 2001-3-26, goto monday: " . getDateWithModifier("2001-3-26", "Monday") . "; should be 2001-3-26.<br>\n"; print "from 2001-3-27, goto monday: " . getDateWithModifier("2001-3-27", "Monday") . " ; should be 2001-4-2.<br>\n"; print "<hr>\n"; print "PHP version: " . phpversion(). "<br>\n"; ?> ======================================================= Produces this output: ======================================================= [EMAIL PROTECTED] tmp]# ./script.php <hr> from 2001-3-17, goto monday: 2001-3-19; should be 2001-3-19.<br> from 2001-3-18, goto monday: 2001-3-19; should be 2001-3-19.<br> from 2001-3-19, goto monday: 2001-3-19; should be 2001-3-19.<br> from 2001-3-20, goto monday: 2001-3-25; should be 2001-3-26 ###.<br> from 2001-3-21, goto monday: 2001-3-25; should be 2001-3-26 ###.<br> from 2001-3-22, goto monday: 2001-3-25; should be 2001-3-26 ###.<br> from 2001-3-23, goto monday: 2001-3-25; should be 2001-3-26 ###.<br> from 2001-3-24, goto monday: 2001-3-25; should be 2001-3-26 ###.<br> from 2001-3-25, goto monday: 2001-3-25; should be 2001-3-26 ###.<br> from 2001-3-26, goto monday: 2001-3-26; should be 2001-3-26.<br> from 2001-3-27, goto monday: 2001-4-2 ; should be 2001-4-2.<br> <hr> PHP version: 4.2.3<br> [EMAIL PROTECTED] tmp]# ======================================================== Expected output: The 6 lines with "###" are expected to produce the indicated output, but do not. Problem was noticed today in PHP 4.06, and then verified as being reproducible in PHP 4.2.3 (same output). PHP 4.2.3 configured with: ./configure --with-mysql --enable-xml --enable-wddx ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=20382&edit=1
