TZ Environment Variable: IANA Zone Name vs POSIX String Parsing
Time Zone Selection Behavior The TZ environment variable is used by Unix systems to determine the local time zone for functions like localtime() . According to POSIX standards, this variable can accept either a POSIX TZ string (e.g., EST5EDT ) or a path to a zoneinfo file, typically prefixed with a colon to indicate an IANA zone name (e.g., :America/New_York
unix