It's not necessary, but that's the shortest way, and that's what all the airlines do.
1 day
how long dose it take to cross the international date
They do.
No. The International Date Line does not go through China.
kiribati
24
the Pacific Ocean
Since the earth is a sphere, there are at least two different ways to get from any place to any other place ... a longer way and a shorter way. To travel from Barcelona to London, you could set out in a south-southeasterly direction, eventually cross the International Date Line, and reach London after a total journey of about 24,190 miles. You could certainly do that. But anyone who looked at a map or a globe before leaving Barcelona would probably choose to set out in exactly the opposite direction. He would not cross the IDL, and his total journey before reaching London would amount to only about 700 miles. To each his own. The choice is entirely up to you.
No.
yes.
east-bound