This article covers
Mail merge timestamp timezone
Solution
You have included {{subscription.created_at | format : dd-MM-yyyy }} mail merge timestamp in your email template, but the format is still displayed as 20-Aug-2022 (default format) instead of 20-08-2022 when you send test emails.
Date formats won’t be applied in test emails as you use static data for mergevars.
Test emails are meant to be used only for checking out the look and feel of the template in
different mail clients (especially when a custom HTML template is configured).
To test different date formats, please send an actual mail.
Instead of repeatedly editing and saving the base templates, you can use the “Edit” functionality to send sample emails with different date formats.
Here’s how the yyyy-MM-dd format will look:
Related articles and Documentation
Mail Merge Fields For Formatting Timestamp