EVER got off a red-eye flight and felt like a walking zombie?

Blame it on jet lag, a condition that arises when a traveller feels out of sync with the current time zone. Its symptoms - like fatigue, disorientation and an inability to sleep - can ruin a holiday.

Now, British Airways' new Jet Lag Advisor is hoping to put the matter to rest.

Created by the airline's resident Dr Sleep Chris Idzikowski, the online adviser allows travellers to get tips on when they should 'seek' or 'avoid' light.

Light, explains the adviser, is one of the 'primary cues that the body clock uses to maintain its link with the outside world'.

Simply key in information like your usual bedtime, whether you are a good or bad sleeper and your time zones.

Click a button and, voila, this handy tool tells you exactly what times of the day you should grin and bare with light, and when you should go into hibernation mode to counter the effects of jet lag.

For the former, daylight is best. But if it's not available, a bedroom light is sufficient to minimise the effects of jet lag, it says.

For the latter, drawing all curtains to cut off light or wearing an eye mask is also one way to condition your body to a new clock.

There's one last thing we hope it could tell us though: how to get bumped up to First Class so we can sleep like a baby.