[Django]-Setting SECURE_HSTS_SECONDS can irreversibly break your site?

HTTP Strict Transport Security

HTTP Strict Transport Security lets a web site inform the browser that
it should never load the site using HTTP and should automatically
convert all attempts to access the site using HTTP to HTTPS requests
instead. It consists in one HTTP header, Strict-Transport-Security,
sent back by the server with the resource.

In other words, if you set the value of SECURE_HSTS_SECONDS to e.g. 518400 (6 days) your web server will inform your client’s browser the first time he visits your site to exclusively access your website over https in the future. This applies to the entire defined period. If for any reason you no longer provide access to your website over https the browser couldn’t access your services anymore.

Therefore, you should initially set this variable to a low value of like 60s and make sure that everything works as expected, otherwise you could prevent yourself and your client from visiting your site.

Browsers properly respecting the HSTS header will refuse to allow
users to bypass warnings and connect to a site with an expired,
self-signed, or otherwise invalid SSL certificate. If you use HSTS,
make sure your certificates are in good shape and stay that way!
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