This reminds me of when aah wez on my Senior Meteorologists Course doon in Cornwall when aah wez in the RN.

As yez may, or may not know, all meteorological information, worldwide, is gathered in Greenwich Mean Time.

Me and Billy Kerr decided we wouldn't gan oot for a beer until a certain time of an evening

Now as Britain was either in GMT or BST (British Summer Time)this posed a problem so.............

We designated that we would go out for a drink at 2100 EGT (Evening Glopping Time - Gloppin' is a naval term for drinkin', but yez knew that aalready)

2100 EGT is the exact time that the sun on its peripheral diurnal trajectory is designated to be 'Over The Yardarm' as defined by Sir Cloudsley Shovel prior to his demise when HMS Association sank off The Scilly Isles in 1707.

As EGT is an ETZ (Elastic Time Zone) 2100 EGT can be estimated at anywhere between 0800 and 0759 depending on;

a. The height of the thirst and,
b. The Depth of the pocket.

That's Official!