Also available as an extension for Visual Studio Code.
Syntax highlighting is provided for the raw time zone definition files:
As well as associated metadata files:
If you really want, you can use the old-school manual installation method (but using Package Control is easier):
Find your package installation path with Sublime Text by selecting Preferences -> Browse Packages...
Then open that directory in a terminal and run
git clone https://github.com/gilmoreorless/sublime-zoneinfo.git
For consistency, any changes to syntax highlighting made in this package should also be made in vscode-zoneinfo.
This code is open source under the MIT license – © Gilmore Davidson.