Is it sufficient to intend only one time to fast the whole month of Ramadan?
One must observe the intention for fasting before the fajr. However, if he did not do so, his fasting is invalid. Allah said ( interpretation of the meaning ) : { And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset.} Quran ( 2 : 187 )The correct view is that it is sufficient to intend to fast the whole month of Ramadan before the first night begins, one is not required to intend fasting every night. Unless there is a Sharia approved excuse that permits one to break his fasting then he may break his fasting and then intend to fast again after this excuse elapses.
Allah said ( interpretation of the meaning ) : { The month of Ramadhan [is that] in which was revealed the Qur'an, a guidance for the people and clear proofs of guidance and criterion. So whoever sights [the new moon of] the month, let him fast it; and whoever is ill or on a journey - then an equal number of other days. Allah intends for you ease and does not intend for you hardship and [wants] for you to complete the period and to glorify Allah for that [to] which He has guided you; and perhaps you will be grateful.} Quran ( 2 : 185 )
