The rub is that the reason why the various time zones used in practice today is spawned by the fact that the decision for administration of time zones is done at the individual nation level, rather than basically through the United Nations, because the time zones are decided more or less in terms of what economically speaking is practical for a particular environment.
Biggest examples: China, regardless of the fact that it spans 5 time zones, uses China Standard Time (UTC + 8) for the entire nation. India, while it spans 3 time zones (westward towards Pakistan, and Bengal in the east), still uses India Standard Time for the entire nation (UTC + 5:30).
Asking nations to all fall to one time standard (which may or may not economically speaking work well in individual circumstances) seems to be a pretty tall request.
Biggest examples: China, regardless of the fact that it spans 5 time zones, uses China Standard Time (UTC + 8) for the entire nation. India, while it spans 3 time zones (westward towards Pakistan, and Bengal in the east), still uses India Standard Time for the entire nation (UTC + 5:30).
Asking nations to all fall to one time standard (which may or may not economically speaking work well in individual circumstances) seems to be a pretty tall request.