* Feature - Charge an additional cost (delivery fee) for choosing specific delivery days and time frames.

* Tweak - Removed the option 'auto' in favor of the option 'required' in the 'Delivery fields' setting.

* Tweak - Hide the delivery fields in the checkout form when there are no available dates.

* Tweak - Keep the delivery fields' values when refreshing the checkout form.

* Tweak - Prevent the interaction with the delivery fields while the checkout fragments are being refreshed.

* Tweak - Validate the 'Delivery days' form field is not empty when adding a time frame to multiple delivery days.

* Tweak - Display the info 'Number of orders' in the 'Description' column of the 'Delivery days' setting table.

* Tweak - Don't display the delivery estimation text when the range of days is zero. 

* Tweak - Added a link to get support in the plugin list.

* Tweak - Improved formatting of the System Status Report.

* Tweak - Tested compatibility up to WC 6.5.

* Tweak - Tested compatibility with WP 5.9.

* Fix - Fixed a double triggering of the event 'update_checkout' when clearing the value of the delivery date picker.

* Fix - Fixed compatibility issue for PHP 8.1.

* Dev - Use a WC background process to handle the plugin updates.

* Dev - Use a trait instead of a class for implementing the Singleton pattern.

* Dev - Added custom tables for storing the time frames' data.

* Dev - Added data stores for handling the delivery days and time frames.

* Dev - WC Subscriptions v2 is no longer supported.

* Dev - Dropped deprecated plugin code up to version 1.7.

* Dev - Deprecated the access as an array to the data properties of a `WC_OD_Data` object.

* Dev - Deprecated custom setting field `wc_od_day_range`.

* Dev - Updated the minimum requirements to WC 3.5, WP 4.7, and PHP 5.4.

Tweak - Tested compatibility with WC 6.0.

* Feature - Added setting to include a description in the delivery section on the checkout page.

* Tweak - Tested compatibility with WC 5.9.

* Tweak - Added plugin info to the WooCommerce System Status Report.

* Tweak - Tested compatibility with WC 5.8.

* Fix - The delivery date was still available when all its time frames were full (Only when restricted by shipping methods).

* Tweak - Tested compatibility up to WC 5.7.

* Tweak - Tested compatibility up to WP 5.8.