Skillset for unit-testing

I have two questions regarding this topic:

1. 
   

   How long does it take for you to create unit-tests? Take a project for a web-application, and you are working TDD. How long time does it take for you to create all the unit tests? Hypothetically. 1 hour? 1 day? 1 week? 1 month? Basically, I want to know whether creating unit tests is a quick task or not.

   
   


2. 
   

   Is creating unit tests difficult? Does it require a lot of programming skills? You call a method, you inject values and you compare the expected value to the actual value. This does not seem complex, or is it?