The hour when the lunar sphare moves away from the Sun’s vicinity is called divij. Sight of the noon is
not entered in any calendar till the
hour of Parwa remains (16th day of
the month). However, when the time of
divij arrives inferential sight of moon is established. Here inferential means
the tradition of establishing sights of moon, particulary on 29th of Hijrah
calendar. The reason is that the hour of divij in one month begins in the
morning while in another at noon or near the evening. The month in which divij
starts in the morning is found to be of 30 days. General characteristic of the
moon of 29th day is that its initial part is of parwa. Then comes dvij.
Mathematicians and astronomers ponder that day over calculation of devij. If
its magnitude covers from the noon to the evening then moon sight to them is
evident. In case the magnitude of dvij is less than the span from the noon to
the evening or in some of them remains for just a quarter day recording of moon
sight is quite inferential and dubious. This is because magnitude of dvij for
appearing and sighting of the moon varies. When the moon is not sighted on the
established magnitude of dvij there starts summer season in India.