The Saudi astrophysicist also supervisor of Zu'aq Astrophysics Observatory Dr. Khalid bin Saleh al-Zu'aq said that he expects tomorrow (i.e. Monday) to be the first day of Shawwal 1435H (i.e. first day of Eid al-Fitr) according to Umm al-Quora Lunar Calendar Calculation Method.
Al-Zu'aq was quoted by al-Madina newspaper as saying that since the moment of birth of Ramadan's crescent, the moon kept moving behind the sun apparently eastwards, and as the speed of the moon exceeds that of the sun a little, and the moon follows the sun in earnest it will finally reach the sun on Sunday 27 July at 1:42. Therefore, the new moon of Shawwal will be born universally as the sun and the moon at that particular moment will be on a parallel celestial line, he said.
He said that the facial luminosity of the moon will be 0.6%. The shape of the moon will be curvilinear with both of its horns moving southwards. at a distance of 40,207 km from the Earth, he added.
The moon will become full moon on Sunday at 7:11 pm, he explained.