It is not that easy to keep in memory all the date format marking.
The application will help you to simply pick the correct format even if you have no Internet connection!

Date Formatter Tool provides you intuitive playground to apply different configurations.
Once you pick one, generate Swift code and paste it into your project.
If you have any difficulties with raw date format, just watch the information reference by pressing cmd + i.

The application is made for Cocoa developers of any level.
It will be suitable extension to your development workflow.