After the sun has set, one should not delay in breaking the fast. It is reported in Musnad Ahmad that the Prophet (s) said, "My ummah will remain upon good so long as they delay the suhoor, and hasten in iftar (after the sun has set)." It is reported in another hadith in Sahih al- Bukhari that the Prophet (s) said, "The people will remain upon good so long as they hasten in iftar (after the sun has set)." (Musnad Ahmad, 21507) (Bukhari, 1957)