This year, their answer has been: "Either on June 15 or 16".
The end of Islamic holy month of Ramadan is marked by the key Muslism festival of Eid al-Fitr, in which Muslim families gather for the "feast of breaking the fast".
Muslims are now nearly at the end of their month-long fasting period known as Ramadan, which began on 16 May 2018.
The Central Ruet-e-Hilal Committee will meet on Thursday evening in Karachi for Shawal moon sighting. If the moon is spotted on Thursday night, the first day of Shawwal will be on Friday which will also be the first day of Eid Al Fitr.
An expert privy to the matter told The Express Tribune that there are nearly "no" chances of Shawaal moon sighting on the eve of June 14. The time when Eid starts also depends on where you are in the world, and when the new moon is seen.
A statement released by the Ministry says the holiday is to mark the celebration of Eid-ul-Fitr across the country. There are, however, exceptions, as some sects have more strict rules to establish that the moon has been sighted and rely on individual testimony than the scientific methods. After that, all eyes will be set on the sky to spot the moon.
Private sector staff will be off for the first and second days of the month of Shawwal (expected to be either Friday and Saturday or Saturday and Sunday), the ministry said on Twitter.