Staying awake all day to try and reset your body clock.

Normally follows after a sequence of going to sleep at increasingly later times, until your going to sleep around dinner. The only cure is to hack it through the day and go to sleep at a sensible time.

A play on the phrase all nighter; used to describe the almost impossible feat of staying up all day without napping.

instead of an all nighter, where as most people fall asleep as soon as morning comes around, an all dayer extends it another 24 hours. This makes it a 48 hour awake period.

A marathon drinking session which starts around lunch-time and carries on until dawn. Typically involves barbecues and beer gardens in Summer and warm pubs and Christmas jumpers in winter.