I felt so humble and said to my father, “It is time I should fast the month of Ramadhan, and I shall start…

Answer

You should be able to know that by sighting the new moon in your country or nearby countries that share the same horizon; in other words, if the crescent is sighted in one country, it should be seen in the other, were it not for natural barriers, such as clouds, mountainous terrain, and the like.