I don't understand your point. The module he is using is quite aware as to when Chicago uses DST and when it doesn't. 
print(fromGMT('20090101', '12:00:00'), "\n");  # 06:00:00
print(fromGMT('20090701', '12:00:00'), "\n");  # 07:00:00

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In reply to Re^2: GMT to Chicago TIme by ikegami
in thread GMT to Chicago TIme by Anonymous Monk

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