Fail to enable booking time slot in D7
The modules that in that list are followed by "(missing)" are the modules that are not present in the Drupal installation, and that are required from the module you are trying to install. Just install them, and you will be able to install the Booking Time Slots module.

The trick is understanding which modules you need. Since the modules are not found on the server, what the module page shows is not the module name, but the short name of the module capitalized.

The list of the modules that site needs is the following:


Entity API
Entity reference
Features
Hierarchical Select
Opening hours


As you see, the module pages says that the Opening_hours module is missing, but the module name is Opening hours, while opening_hours is the short name of the module, the same used in the URL for the project page. Join https://drupal.org/project with opening_hours, and you get the complete URL of the project page for the module you are looking for: https://drupal.org/project/opening_hours.  

The list of modules is shorter because there are modules that are sub-modules of modules already listed as requirements.

The Opening hours module then depends from the following modules:


Date Popup (part of the Date module)
Tipsy