Bug #9640 Updated: strtotime() cannot properly handle some ISO 8601-compliant strings

ID: 9640 Updated by: derick Reported By: derekm@hackunix.org Old-Status: Open Status: Assigned Bug Type: Date/time related Operating system: PHP Version: 4.0.4pl1 Assigned To: derick Comments: Previous Comments: --------------------------------------------------------------------------- [2001-03-08 17:26:17] derekm@hackunix.org I've recently run into a problem. This problem has been addressed in bug report #9007, but I thought I would try to provide more detailed information. First, I'm pulling ISO 8601-compliant date strings from a PostgreSQL 7.0.3 database. We'll illustrate this bug with a sample date: 1999-06-24 00:01:00-05. Or June 24, 1999, 12:01 AM CDT. $timestamp = "1999-06-24 00:01:00-05"; $timestamp = strtotime($timestamp); print(strftime("%A, %B %d, %Y %H:%M %Z", $timestamp)); Now, that output /should/ read "Thursday, June 24, 1999 00:01 CDT," instead it reads "Wednesday, June 23, 1999 19:06 CDT." Even though PHP knows the timezone of the machine to be CST6CDT, it subtracts 5 hours from the time during conversion, regardless. This is a Bad Thing(tm) because all programs should be ISO 8601-compliant. Currently PHP4 is a lil' broken. This should be fixed in the next release of PHP4, IMHO. The bug probably actually resides in the code in ext/standard/parsedate.c that is borrowed from GNU Bison 1.28. So maybe this bug should be reported to GNU's bug list as well. In any case, here's a fix in the meantime... If using PostgreSQL issue the command "SET DATESTYLE TO Postgres;" in all of your queries that return a timestamp. That will cause the timestamp to be returned in this style: Thu Jun 24 00:01:00 1999 CDT. This style will correctly parse, as we will illustrate with this example: $timestamp = "Thu Jun 24 00:01:00 1999 CDT"; $timestamp = strtotime($timestamp); print(strftime("%A, %B %d, %Y %H:%M %Z", $timestamp)); The output of this example is "Thursday, June 24, 1999 00:01 CDT," which is correct. And that's all. Derek P. Moore derekm@hackunix.org --------------------------------------------------------------------------- [2001-03-08 17:16:14] derekm@hackunix.org I've recently run into a problem. This problem has been addressed in bug report #9007, but I thought I would try to provide more detailed information. First, I'm pulling ISO 8601-compliant date strings from a PostgreSQL 7.0.3. We'll illustrate this bug with a sample date: 1999-06-24 00:01:00-05. Or June 24, 1999, 12:01 AM CDT. $timestamp = "1999-06-24 00:01:00-05"; $timestamp = strtotime($timestamp); print(strftime("%A, %B %d, %Y %H:%M %Z", $timestamp)); Now, that output /should/ read "Thursday, June 24, 1999 00:01 CDT," instead it reads "Wednesday, June 23, 1999 19:06 CDT." Even though PHP knows the timezone of the machine to be CST6CDT, it subtracts 5 hours from the time during conversion, regardless. This is a Bad Thing(tm) because all programs should be ISO 8601-compliant. Currently PHP4 is a lil' broken. This should be fixed in the next release of PHP4, IMHO. The bug probably actually resides in the code in ext/standard/parsedate.c that is borrowed from GNU Bison 1.28. So maybe this bug should be reported to GNU's bug list as well. In any case, here's a fix in the meantime... If using PostgreSQL issue the command "SET DATESTYLE TO Postgres;" in all of your queries that return a timestamp. That will cause the timestamp to be returned in this style: Thu Jun 24 00:01:00 1999 CDT. This style will correctly parse, as we will illustrate with this example: $timestamp = "Thu Jun 24 00:01:00 1999 CDT"; $timestamp = strtotime($timestamp); print(strftime("%A, %B %d, %Y %H:%M %Z", $timestamp)); The output of this example is "Thursday, June 24, 1999 00:01 CDT," which is correct. And that's all. Derek P. Moore derekm@hackunix.org --------------------------------------------------------------------------- ATTENTION! Do NOT reply to this email! To reply, use the web interface found at http://bugs.php.net/?id=9640&edit=2