The Kitáb-i-Aqdas
Author: Bahá’u’lláh
Source: Bahá’í World Centre, 1992 edition
Pages: 254
Page 172   
 

17. In regions where the days and nights grow long, let times of prayer be gauged by clocks and other instruments that mark the passage of the hours. # 10
 
This refers to territories situated in the extreme north or south, where the duration of days and nights varies markedly (Q and A 64 and 103). This provision applies also to fasting.
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