I think Tim and Guido had deliberately avoided local timezone awareness when they designed the module.

Also, I question whether the proposed API is correct.  ISTM that any code that sets the *dst* parameter is guaranteed to be wrong (hardwiring-in a value that will change every few months).

Have you studied the solutions used in other libraries and other languages?  This path has been well-traveled, so original work may be less helpful than just researching existing solutions.