¥@¬É¤£¦P¸g½n«×¦a°Ï§I¤Ó¶§®Éµ{¦¡
¸g«×: 120 E
target ¸g«×: x E (or -x W)
24¤p®É/360 degree = 1/15;
®É¶¡®tÉÝ(¤p®É) = (120 -x)/15
e.g. Washington DC Longitude: 77¢X, West
®É¶¡®tÉÝ(¤p®É) = (120 -(-77))/15 = 13.1 ¤p®É.
e.g Washington DC time = 1:30 am
¤Ó¶§®É = 1:30 am + 13.1 ¤p®É. ~= 2:36pmX