When the broad themes of Shabads are overlaid with feelings conveyed by these raags, there emerges a reason behind grouping of Shabads under a broad classification of thirty-one raags. It’s clear that the Gurus used raags to increase the delivery power of shabad to our mind by invoking complementary feelings in our hearts through usage of the prescribed raags.

Another interesting aspect of raag and Gurbani classification is understood by studying daily time-cycles. A raag has a preferred timing associated with it. There are some morning raags, evening raags, afternoon raags, etc. The timings of raags also complement the changes in human moods and heart during a twenty-four hour time cycle.

Upon classification of thirty-one main raags used in Guru Granth Sahib based on the prescribed raag timings, we find that no raags fall under the time zone 12 AM - 3 AM. It is interesting that the Gurus chose not to use any raag with a time cycle of 12AM – 3 AM, because one would normally sleep between 10PM - 4AM.