Perfect 
Just to show you what I meant:
iex> Tzdata.zone_exists?("MST")
true
iex> Tzdata.zone_exists?("MDT")
false # <- see here
iex> Timex.now("MDT")
#DateTime<2020-03-26 19:55:03.637000-06:00 MDT MST7MDT>
“MDT” doesn’t exist as a time zone ID, but Timex will find a time zone ID that contains the string “MDT”, and finds MST7MDT, whish does change according to US DST rules.
Ouch… I don’t know why Timex would not return an error instead honestly, that leads to bugs ;-p
If one ever needs a fixed offset, better use a time zone ID such as Etc/GMT-7.
Anyway, it was just to complete the information. You use the right time zone ID now.
