Moon sighting and astronomical calculation
Pakistan starts a month on a sighting, not a calculation. Calculation still tells you what to expect. calendar.pk uses both.
What the committee does
The Central Ruet-e-Hilal Committee meets on the 29th evening of a Hijri month. It collects sighting reports from across Pakistan and announces whether the new month starts the next day. Its decision is the official one.
What calculation does
Astronomy can work out where the moon will be years ahead, so it can tell you when the crescent is likely to be visible. It cannot tell you whether cloud, dust or haze will hide it on the night.
How calendar.pk uses both
Dates start from the Umm al-Qura tables so a whole year can be shown in advance. A month that has already begun is settled, so it is marked Confirmed. A month still ahead is marked Calculated. An announcement from the committee corrects the start date.
Common questions
Which one is more accurate?
For the official Pakistani date, only the committee decides. For planning ahead, calculation is the only option.
Why show calculated dates at all?
So you can plan. A Ramadan or Eid date months ahead can only ever be calculated. The page tells you which one you are looking at.
When does a calculated date become confirmed?
Once the month has begun. A committee announcement can also correct the start date, and that correction wins over the calculation.