Translation

時差ぼけ / 時差疲労

Meaning

The physical tiredness and disorientation caused by travelling rapidly across multiple time zones, which disrupts your body's internal clock. 'I still have jet lag after my flight from Tokyo to New York — I keep waking up at 3am.' Note: 'jet lag' is two words, not one. You 'have jet lag' (not 'have a jet lag' or 'be jet lagged' — though 'jet-lagged' as an adjective is also correct: 'I feel jet-lagged'). The condition happens because your circadian rhythm (体内時計) is still set to your home time zone.

Examples

• ニューヨークに着いたとき、ひどい時差ぼけに悩まされた。
  When I arrived in New York, I suffered from terrible jet lag.
• 時差ぼけを克服するのに3日かかった。
  It took me three days to get over the jet lag.