When travelling short distances by airplane the effect of jet-lag can be ignored. But when travelling about 7 or 8 hours or more jet-lag can’t be avoided.
In north to south, or south to north, journeys, like from the UK to South Africa, or from Australia to Japan, there is little or no change in the time-zone, so there is no real jet-lag, just tiredness.
But when I travel between Japan and the UK the flight can take 11 or 12 hours and the time difference is 9 hours. This really affects my natural body-clock and leads to jet-lag.
One thing I’ve noticed over the years is that travelling from east to west (Japan to UK) causes more jet-lag than when travelling from west to east (UK to Japan). Has anyone had any similar, or different, experience?