Before clocks, the Punjabi day was divided into eight pehars of about three hours each, four of day and four of night, and the pehar is still used in speech and in scripture.
The amrit vela, the ambrosial hours before dawn, is the last pehar of the night and is the time prescribed for simran.
Smaller divisions were the ghari, about twenty-four minutes, and the pal. Time in a village was told by the sun, by the call from the mosque, and later by the gurdwara's morning kirtan.
Sohila, the night prayer, and the rehras at sunset mark the ends of the working day in an observant household, and they still do.
The desi calendar, the pehar and the sangrand are all still in use alongside the clock and the Gregorian date, and older people move between the two systems without noticing.
A Punjabi farmer may know exactly what time the free power comes on and reckon the sowing date by the month of Katak.
The night was called and kept. A chowkidar walking a village struck the hour on a piece of iron or called it aloud, and the phrase for the small hours, so many pehar of the night gone, is what somebody half awake heard and turned over on.
The count began at sunrise, so a pehar's actual length shifted with the season, which is how time works when it is measured against the sun rather than a clock.
The gurbani uses those divisions. The banis are set to them, and the nitnem's shape follows a day counted this way rather than a day counted in hours.
Guru Granth Sahib Ji on the pehars and the amrit vela.