Set a time zone in Bun
Bun supports programmatically setting a default time zone for the lifetime of the bun process. To do set, set the value of the TZ environment variable to a valid timezone identifier.
When running tests with bun test, the timezone is set to UTC to make tests more deterministic.
process.env.TZ = "America/New_York";
Alternatively, this can be set from the command line when running a Bun command.
TZ=America/New_York bun run dev
Once TZ is set, any Date instances will have that time zone. By default all dates use your system's configured time zone.
new Date().getHours(); // => 18
process.env.TZ = "America/New_York";
new Date().getHours(); // => 21