One minute it's the new school year and the Christmas holiday seems aeons away. Then you turn around, and suddenly you're putting up decorations and practising carols.
But it's a good excuse for a party. Other ends of term don't have quite the same potential. Easter tends to be bit of a non-event as everyone staggers home with bags full of marking and school development plans. And summer term usually peters out in exhaustion. But at Christmas people still have enough energy to celebrate.
As we might expect, different schools do this in different ways.
Secondaries have the advantage because they can get away with releasing pupils early and starting the serious partying at 2pm.
This can have some predictable consequences. Early in my teaching career I staggered home after an end-of-term session to find my wife doing the ironing. In response to my amazement that she was ironing in the middle of the night she pointed out that it was 8.30am.
In that school teachers would file into the staff room after the pupils had been dismissed to be welcomed by a barrel of Adnams, which had been delivered that morning by a bemused drayman. When that was empty the survivors would decamp to the local rugby club, where the serious drinking would start.
In another school, pupils were roped in as coolies and given the task of hauling the tinnies up to the staff room.
"Oo's 'avin all these?" Darren would ask, not quite believing that the pillars of rectitude who told him off all year would stoop so low as to let the demon drink pass their lips.
Unfortunately for staff, these sessions were curtailed after a particularly riotous end of term that involved a water fight and a competition to build the biggest tinnie mountain. In the end, humanities won the day - while the technology department argued about the design, their opponents focused on amassing building materials. Thus did the amateurs reach the ceiling first.
That evening, parents coming in for the end-of-term concert were treated to the sight of a well-oiled maths teacher being carried out of the building by three similarly incapable colleagues.
"Not good," said the head the following January. But he was one to talk - as I recall, the water fight had been his idea.
At the local primary school the last day was child-centred - there were class plays and a multi-faith service in the afternoon. Staff celebrations were limited to a break-time glass of sherry. And probably just as well - most teachers were still hung over after the weekend's night on the town.
Highlights of the evening included the deputy head's pathetic bid to chat up a succession of bemused blokes and an embarrassingly wayward neckline that led to some frantic attempts to stuff a couple of escapees back into the push-up bra whence they came.
Neutral territory is a good plan for these events. One school had a tradition of house parties hosted by the senior management team. These were characterised by junior staff making caustic comments about the decor while the hosts tried to keep the malt whisky hidden and the carpet free of stains. One party spilled out into a vast garden, where someone fell over a wall and broke a leg. The head was furious about losing a scientist for half a term.
Office parties are reputed to be steamy affairs, with couples disappearing into stock cupboards to have illicit sex on the boardroom table. Perhaps I missed something, but end-of-term school parties have little sexual tension. That may be because the blokes - far from being Andrew Lincoln look-alikes - are actually 40-plus (in age as well as waistline). Or it could be that teachers talk shop even when they're sloshed. Rather than exchanging well-crafted chat-up lines the couple in the corner are more likely to be discussing whose turn it is to mark this year's coursework.
I'm told that things are different now - that staff celebrations are much more sensible, and teachers today would never be found conga-ing in the corridors. So the Lancashire school where the police were called last year after a party led to complaints from neighbours - whose houses were 200 yards away - must be the exception then?
Phil Revell's last staff party was in 1996 - he thinks.