IOS App Xcode Project Help

I'm looking for some help coding my app (must be Swift 4). I don't need you to create an app for me, just provide the Xcode project files with Swift code written.

Basically, I have 3 input boxes, one where you input a day of the week, one where you indicate the frequency (probably, 7, 14, or 21 days), and one description for example, Red, Green).

The user will enter these details on a set up screen then simply there is a label on the main view controller that would say which week is next. For example if the user entered the day as Friday, the original date as 6th July, the frequency as 14 days, and the description as Red, then anytime from Saturday 14th July to Friday 20th July the label would simply say "This Friday starts your Red week".

Assuming the user had set up Green in the same way but a week later, then anytime from Saturday 21st July through to Friday 27th July it would then say "This Friday starts your Green week".

Hopefully, I've explained that correctly, but it is something really simple if you are an experienced developer, probably just 1 hours work. I've been trying NSCalendar and been user UserDefaults to try and add 14 days each time but can't quite get it to work.

Any questions please ask!