Date standardization

Getting custom date fields set correctly

Note: This guidance is only required if you have modified the structure of your database to add custom date fields.

Handling custom date fields in your database

Zen Cart uses a specific string (rather than NULL) for date fields to indicate that the date has not been set.

In older versions of Zen Cart, the string was 0000-00-00. However, since then, MySQL has updated their definition of allowable date formats to exclude this string.

Since Zen Cart 1.5.6, the upgrade process has included steps necessary to fix these older style dates as follows

  • update all rows in the table to change with the value 0000-00-00 to 0001-01-01
  • set the table’s default value to 0001-01-01.

(In the case of datetime values, the appended value for time, 00:00:00, has not changed.)

However, the upgrade process can only do this for built-in fields. If you have customized your database to include additional fields (perhaps via a plugin, or perhaps with your own custom code), you will need to make the same changes to your own database.

Examples of plugins which create or add a date field are as follows:

To get the custom datetime field order_delivery_date into the new format, use following command in phpMyAdmin or in Install SQL Patches:

UPDATE orders SET order_delivery_date = '0001-01-01 00:00:00' WHERE CAST(order_delivery_date AS CHAR(19)) = '0000-00-00 00:00:00';

or if the field were just a date field then:

UPDATE thetablename SET thefieldname = '0001-01-01' WHERE CAST(thefieldname AS CHAR(10)) = '0000-00-00';

To update the default value of the field, you would do something like

ALTER TABLE thetablename MODIFY COLUMN thefieldname datetime NOT NULL default '0001-01-01 00:00:00';

Note: If you run that command via phpMyAdmin and your site uses a DB_PREFIX (e.g. zen_), you will need to add that prefix to any database table name. For the example above, you’ll replace orders with zen_orders.

For reference, the script that does the date updating is stored in zc_install/sql/install/zero_dates_cleanup.sql.




Still have questions? Use the Search box in the upper right, or try the full list of FAQs. If you can't find it there, head over to the Zen Cart support forum and ask there in the appropriate subforum. In your post, please include your Zen Cart and PHP versions, and a link to your site.

Is there an error or omission on this page? Please post to General Questions on the support forum. Or, if you'd like to open a pull request, just review the guidelines and get started. You can even PR right here.
Last modified June 14, 2021 by Scott C Wilson (52940a7).