Discussion started on #72.

I've modified this plugin to control in which time range can each page be decrypted, using the attributes start_time and end_time in each page.meta.

Basically, I've added a <div id="mkdocs-encrypted-config"> with a dictionary of config options, which includes start_time and end_time. The dictionary is encrypted with the same key as the content page.

The reason for this instead of a <input hidden> is that in this way is easy changing the config values directly from the HTML.

In the decryption process, I decrypt the config and I check if the current time is between that time range. If so, I let the page be decrypted.

inside_time_range = {% if webcrypto %}await {% endif %}decrypt_config_action(
    username_input, password_input, encrypted_config
);

if (inside_time_range) {
  key = {% if webcrypto %}await {% endif %}decrypt_action(
      username_input, password_input, encrypted_content, decrypted_content
  );
  decryptor_reaction(key, password_input, decrypted_content);
} else {
    let mkdocs_decrypt_msg = document.getElementById('mkdocs-decrypt-msg');
    mkdocs_decrypt_msg.textContent = decryption_failure_timerange_message;
    password_input.value = '';
    password_input.focus();
}

The code is available at: https://github.com/joapuiib/mkdocs-encryptcontent-plugin/tree/feature/time-range

This doesn't provide any kind of added security. It wouldn't be hard to bypass with JS if you know the password of the page, but I think this is enough for me at the moment.

If anyone wants to try to improve it, any help is welcome.