Clark trading and logistics UK

 The city spent more than 1,000 hours under alert during raids from 19 June 1940 to 1945, with a total of over 1,200 people in the city killed as a result of the bombing.

1000 hours = at 1 Hour a night every night for 2 and 3/4 years 
or if for 24 hour hours straight it would be 41.6 days 
Thats is a long time to put it in perspective 
But of course it was not either of them it would be numerous hour some night and none others other the course of the blitz 

OUR OBJECTIVE: THE SUPPLY PORT OF HULL

The British Port of Hull, with its multi-purpose dockyards, its wharves and its strategically important industrial sites – this was our target yet again today. Along with the other aircrews of our unit, we took off last night, having taken aboard the bomb load which we intended to deposit to good effect in the middle of the great dockyards .. [..]