I have a D8 site that has been using this module, but recently it started failing to build with composer. This turns out to be a result of the composer.json file in the root of datetime_range_timezone, which requires drupal/core:^9.2. Obviously a Drupal 8 site won't have a Drupal 9 core.
Fix composer.json to allow Drupal 8 projects also.
Needs review
Code
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.
Suggesting we close in favour of 📌 Automated Drupal 11 compatibility fixes for datetime_range_timezone Needs review which removes 8/9 altogether