UTC-7? What's up with that!!!

Problem:
Have the wrong time zones sneak into the code is horrible and disastrous. This needs to be fixed!

Make it so:
- We should only be concerned with UTC-8 (pacific standard time)
- All references to -7 to be removed
- All hard coded -8 values to be removed - we should be using the -8 constants everywhere
- The reason for this should be extremely well documented in code

The issue names no files, tests, or entry points. Start by searching the repository for UTC-7, hard-coded UTC-8 values, and existing timezone constants; then identify the affected code and tests. Done means the unwanted references are removed, the shared constants are used consistently, and the rationale is documented in code.

Written by the indexing model from the issue text.