In journeying eastward he [Fogg] had gone towards the sun, and the days therefore diminished for him as many times four minutes as he crossed degrees in this direction. There are three hundred and sixty degrees on the surface of the earth; and these three hundred and sixty degrees, multiplied by four minutes, gives precisely twenty-four hours - that is, the day unconsciously gained. In other words, whilst Phileas Fogg, going eastward, saw the sun pass the meridian eighty times, his friends in London only saw it pass the meridian seventy-nine times.[20
The International Dateline is not straight because certain countries justified adjustments to keep the same time throughout their territorial area.