From the book "Naam or Word", written by Sant Kirpal Singh
One may devote oneself to the worship of Naam or Word at any time and at any place for there are no restrictions in this behalf. But Amrit-Vela (early dawn) is the most appropriate and fruitful for the purpose.
At the ambrosial hour of the early dawn,
Be ye in communion with the divine Word,
And meditate on His glory.
GURU NANAK
Again,
O thou rise early, and worship the Word day and night, and then,
O Nanak, thou shalt have no grief and escape from all troubles.
GURU RAM DAS