Dynamically reconfiguring time zones in real-time using plural time zone libraries

A computer program product for retrieving local time using a plurality of time zone (TZ) libraries comprising:

• a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:
• receiving, by a TZ management component of an operating system, a request for a local time setting of a computer, wherein the request includes a preferred TZ library, a preferred TZ information data (TZID) version, a preferred TZ name, a plurality of TZ library rules of reconfiguration, and a TZ name retrieval policy;
• searching each of a plurality of TZ libraries and each of a plurality of TZID versions, wherein the plurality of TZ libraries and the plurality of TZID versions are integrated into the operating system, beginning with the preferred TZ library, in a user-defined pre-defined search order, for the preferred TZID version and the preferred TZ name;
• based on the searching returning the preferred TZID version and the preferred TZ name, dynamically loading a corresponding TZ rule for formatting the local time of the computer;
• based on the TZ rule indicating that daylight savings time (DST) is observed, applying the DST rule from the TZ rule for deriving the local time;
• formatting the local time using a system-wide localization rule or a user-defined localization rule.