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Simply Schedule Appointments relies on WordPress to successfully configure the PHP default timezone function to UTC. This is a function that the majority of plugins should not be modifying themselves, but we sometimes come across some that do. When this happens, SSA (and probably other plugins, too) can break and appear buggy.

One of the biggest symptoms SSA shows with this error is that all of your dates and times will shift regardless of whether you’re using the correct timezone in the plugin.

Confirming a PHP Default Timezone Error

There are two ways to confirm whether you’re dealing with this issue.

Check the SSA Support Tab

Go to the SSA Support tab, and if you look under PHP default timezone, there should be a message saying:

“PHP default timezone was changed after WordPress loading by a date_default_timezone_set() function call. This interferes with correct calculations of dates and times.”

Support Tab depicting the PHP Default timezone error.
Error is shown in the SSA support tab

Check the Site Health Panel from your WordPress Dashboard

From your WordPress Dashboard, go to Tools > Site Health. Under Critical Issues, you should see the following error, “PHP default timezone is invalid”.

Site Health displaying the PHP Default timezone error.
Site health panel showing error under critical issues

How to Fix PHP Default Timezone Error

We’ll need to track down the plugin or theme causing this error. To do so, we recommend that you complete the following steps on a staging site if possible or make sure to create a backup on your live site before you continue.

  1. See if it’s a plugin conflict by disabling all other plugins or by using Plugin Detective to identify a conflict quickly.
  2. See if it’s a theme conflict by switching to a default WordPress theme.

We offer a guide to walk you through the troubleshooting process using Plugin Detective.

Once you’re able to narrow down on the culprit that’s modifying the date_default_timezone_set() function, you have two options. Either disable the plugin/theme (if it’s unnecessary or if there’s an alternative one you could use), or you can try contacting the developer and mentioning that WordPress requires the timezone to be UTC in order to function properly.

You could also send them the following article that offers helpful suggestions for fixing this issue in the code itself.

Still stuck?

File a support ticket with our five-star support team to get more help.

File a ticket

  • Please provide any information that will be helpful in helping you get your issue fixed. What have you tried already? What results did you expect? What did you get instead?
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