We need a point of reference a Dateline on the Earth itself to count its rotation, which marks the day. This point would mark the beginning of the day. Towards the west of this point the new day begins while towards the east the old day is ending. As the point of reference would have two days meeting, it cannot be on land where people live. Further, this point ought to be a line running from North to South of the Earth. Now the whole
life has to continuously pass through the sea avoiding land. When we search for such a point on Earth we find it between Russia and Alaska. Interestingly this is the place where the International Date Line runs across. The day begins with this line that comes straight to the Sun at noon. So the day begins on earth at 12noon on the date line. At London, which is to the opposite of this live, it is 12midnight. Our concern here is with the time of the birth of the day on Earth, which is at 12 noon. It is with reference to this that we calculate the time in 24 hours. The universal say is from noon to noon, calculated at the Dateline or midnight to midnight, calculated at London 0 degree Greenwich. The point that is here underlined is that the people of Fiji to the west of the Dateline pray the first Jummah of Friday while people of Samoa to the east pray the last Luhar of Thursday.
The outline of kiblahs too arises here. The people of fiji pray towards the west and the people of samoa towards the east. When the Islamic dateline runs through land there would be two days, jummah and luhar and two kiblahs in the same place. One should interpret the statement of imam Shafee that there can be no two jummahs in the same town against the concept of the Islamic dateline. The learned imam was suggestions that the Dateline should not pass through land.