Why Is CONVERT_TZ() Not Working in My MySQL Queries?

Converting UTC Dates to Local Time Zones in MySQL Queries

To convert UTC timestamps to local time zones in your MySQL queries, you can use the CONVERT_TZ() function. However, it's important to note that using this function may not always be successful.

Why CONVERT_TZ() Might Fail

If CONVERT_TZ() is not working for you, there are a few possible reasons:

• Incorrect Time Zone Specifications: Ensure that you have provided valid time zone identifiers in the CONVERT_TZ() function.
• Empty Time Zone Tables: MySQL relies on time zone tables to perform time zone conversions. If these tables are empty, you need to initialize them using the mysql_tzinfo_to_sql program.

Query Example Using CONVERT_TZ()

The following query converts a timestamp column called displaytime to the MET time zone:

SELECT CONVERT_TZ(displaytime, '+00:00', '+04:00');

Checking Time Zone Tables

To verify if your time zone tables are initialized, execute the following queries:

SELECT * FROM mysql.time_zone;
SELECT * FROM mysql.time_zone_name;

Initializing Time Zone Tables

If the time zone tables are empty, use the following command to load them:

mysql_tzinfo_to_sql /usr/share/zoneinfo

Once the time zone tables are initialized, try using CONVERT_TZ() again. If you still encounter issues, consult the MySQL documentation for more detailed troubleshooting steps:

• [Date and Time Functions: CONVERT_TZ()](https://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_convert-tz)
• [Time Zone Support](https://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html)
• [mysql_tzinfo_to_sql](https://dev.mysql.com/doc/refman/5.5/en/mysql-tzinfo-to-sql.html)

The above is the detailed content of Why Is CONVERT_TZ() Not Working in My MySQL Queries?. For more information, please follow other related articles on the PHP Chinese website!