Is there a difference between the astronomical timing of sunrise and the actual reality?

The Shaykh : And your name is Abdullah?
The student: Yes.

The Shaykh : And you are the one who hastened to do good in the mosque on Friday, and asked about the difference between the astronomical timing of sunrise and the actual one? Is that you?
The student : Yes, it is him.

The Shaykh : Is that you?
The student : It is my colleague who asked... the idea...
Another student: Join him.

The Shaykh : I said this so that you would not be embarrassed by my reminding you. I said: "You hastened to do good." So, what does hastening to do good mean?
The student : Absolutely not.

The Shaykh : Fine, why did you take on the responsibility then?
The student : ...

The Shaykh : Fine, that one, do you not want to hasten to do good, my brother?
The student : ...Hasten to do good...
Another student: He wants to be precise with you, just as you are precise with him.

The Shaykh : Fine. I mentioned something to you in this regard, but it occurred to me, especially since I heard that you are about to travel, that you should see with your own eyes what you have heard with your ears. So, what is your opinion?
The student: All right.

The Shaykh : Fine. Now, the sun rises at approximately 5:45, and in the calendar it is approximately 5:30. So, what is your opinion? Pray Fajr in the mosque closest to our house, and come with a companion if you do not know our house, and break your fast with us. Before breaking the fast, you will see the sunrise with your own eyes, and we will show you the calendar. After that, we will take a second step and say to you: As you can see, we are on a mountain. So, do we see the sun before those in the middle of the city, or after?
The student : Before.

The Shaykh : Is that not so? So, if we see the sunrise according to the calendar a quarter of an hour later, when do those in the middle of the city see the sunrise?
The student : About a quarter of an hour.

The Shaykh : Yes?
The student : About a quarter or ten minutes.
Another student: More.

The Shaykh : It will be more, meaning, for example, our difference is a quarter of an hour, but it might be a third, twenty-five minutes, or perhaps half an hour, depending on the case. We are on a mountain, so the lower a person goes into a valley, the later the sunrise is for them. So, if we are on the mountain and see the sun rise at least a quarter of an hour after the calendar, what is the situation of those in the city? Here you know the danger of relying on the calendar and astronomical science, because many people... do not eat with your left hand, may Allah bless you.
The student : The questioner : Here is the same topic, he tells you.

The Shaykh : Listen a little, let us finish here.
The student: Excuse me.

The Shaykh : Shall we make an appointment for you to come and see with your own eyes, or are you satisfied with what we have said?
The student : No, Shaykh, we want this place.

The Shaykh : Yes?
The student : We want this place.

The Shaykh : He wants this place.
The student : I want it, I will bring him.

The Shaykh : We say to him, welcome.
The student : When? Tomorrow, Monday, my Shaykh, just.

The Shaykh : Tomorrow, Monday. When will you travel?
The student : Tuesday evening.

The Shaykh : Tuesday evening?
The student : Ah, then Tuesday morning.

The Shaykh : Morning, then. Okay?
The student : If Allah wills.

The Shaykh : If Allah wills.