Yes, you can disable the particular time slot in Magento 2 delivery date and time extension. Follow the below instructions:
Login to Backend
Go to Stores ➤ Configurations ➤ AppJetty ➤ Delivery Date, you will land on the “Configuration” page. Now scroll down to the “Time slot settings” section and do the following configurations.
Disable time slot of day: Select the day and time slot you want to keep disabled.
Disable time slot of particular date: Select the Date, Month, Year, and Time Slot you want to keep disabled.
After all the configurations are done, click on the “Save Config” button to save the configurations in your store.