Hello, you can also take a look at this module: http://amasty.com/delivery-date.html. It enables customers to select the preferable delivery day and time as well as create the delivery note where they can specify additional details.
Therefore, with the module you can:
- Enable visitors select days and time of delivery
- Exclude any dates from your delivery plan
- Let customers create delivery messages
- Set minimal and maximal delivery intervals
- Customize delivery data display according to your needs