complete question
If I start Ramadhan in one city and then I travel and finish the month of Ramadhan in another city, what is my duty especially in regards to Laylat al-Qadr or Eidul Fitr? That is because in one city they started fasting on Monday and in another city they started Ramadhan on Tuesday. What should I do? Do I continue what I started or do I follow what the local city is doing?
Concise answer
You must act according to the horizon of the place where you are currently in. Hence, the Night of Qadr and also Eidul Fitr are determined on the same place.
Some grand religious authorities’ answers to this question are as under:[1]
Grand Ayatollah Khamenei (may Allah grant him long life):
You must act according to the horizon of the place where you are currently in.
Grand Ayatollah Makarem Shirazi (may Allah grant him long life):
Wherever you are, you should act according to the horizon of the same place. You must note that ‘night’ means that the shadow of part of the earth falls on the other part. Therefore, if the Night of Qadr starts in Mecca, the Night of Qadr continues until the shadow takes over all parts of planet earth. In fact, the Night of Qadr lasts for 24 hours. There is no more than one night throughout the planet.
Grand Ayatollah Saafi Gulpaigani (may Allah grant him long life):
The Night of Qadr (Laylatul Qadr) is determined depending on when and which day you ascertained the beginning of the month of Ramadhan. The day of Eidul Fitr would then be determined. If the crescent is sighted on the night preceding the 30th day of the month, the following day would be the Eid day; otherwise Eid would be upon completion of 30 days.
[1] The question has been sent by IslamQuest website to the offices of the grand Ayatollah Khamenei, Ayatollah Saafi Gulpaigani and Ayatollah Makarem Shirazi – may Allah grant them long life.
source : islamquest