In a segregation unit far away in time and distance, the night patrol was stomping up and down the corridor in his boots, keeping the prisoners awake. This was rude in the extreme; night staff usually wear appropriately silent footwear lest they disturb their charges.This particular fellow was being ignorant in the extreme, and was subjected to volleys of abuse, all of it unrepeatable for the civilised eye that graces this page.Until, deep into yet another night disturbed by his footfalls, a prisoner's voice sang out from behind his door."Guv", he shouted, "when's Christmas?"The screw, quick as a flash, replied "the 25th".The impatient convict replied "No, I mean, what day does it fall on?"The screw reached for one of the three items of equipment no screw is ever without, his diary, and began leafing through. Much ruffling of pages later, he shouted back to the con "on a Saturday"."Thanks, said the con. We'll make sure we buy you a present then - some FUCKING SLIPPERS"!