Heads up:

The Regional District of East Kootenay is planning to move to year-round Mountain Standard Time (MST) on November 1, 2026. The district will seek approval from the province (British Columbia).  I am skepitcal that they really need provincial approval, but I guess there is no harm in seeking it.

In practical terms the district would move from MDT to MST on November 1 as per usual. After that, the clocks would stay fixed on MST.

Currently most of East Kootenay uses the America/Edmonton TZ ID.  There is a very small area in the southwest corner that uses America/Creston.
If the change is approved, we would need a new TZ ID... probably something like  "America/Cranbrook".

https://www.rdek.bc.ca/news/entry/rdek_board_moves_to_transition_to_year_round_mountain_standard_time

Columbia-Shuswap Regional District lies to the north of East Kootenay Regional District. Some areas of  Columbia-Shuswap are already on year-round MST and some areas (including the town of Golden) use MST/MDT.
I would not be surprised if all of  Columbia-Shuswap eventually adopts year-round MST.  If that happens, the entire province of BC would be aligned on year-round MST.