Which is the best time to recite a particular hymn or to remember God ? all times are equal. But main purpose of gurbani is to help mankind to connect to God hence irrespective of the raaga one can recite any gurbani shabad at any time.
Is there a specific time for reciting specific hymns ? : most part of gurbani is written in raagas and specific raagas have specific times of recitation. Is there a hell according to Sikhism ? : no there is no hell according to Sikhism and Gurbani Sikhism is a concept based religion and this question asks for explaination of various concepts.