Just take a look at the bugfix branch in order to see all the changes so far. Among others, you can see:
- Upgrade CKEditor to 4.10.0
- Fixes to the count notices when using PHP 7.2
- Fix anonymous user images not being displayed
- Fix to a content encoding error when using PHP 5.3
- Change how PHPMailer classes are loaded
- Update hidden HTML to avoid its detection as malware
- Fix missing email confirmation link in user account
There are also some pull requests created for the bugfix branch, but I can't confirm they will be merged or not. Those are here.
Regarding the date, it is not defined at the moment.