This short articles, published in the local newspaper, reports the number of hours which London had been on alert since the enemy air offensive began in August 1941 to mid-January 1942.
To give an idea of how intense the bombing was, it is reported that Hull received just over 1,00 hours of alerts during the whole of the Blitz!
According to a calculation by a news agency reporter, who has kept a daily log of alerts since the enemy air offensive on a big scale was launched during August, London has had warnings totalling more than 1,056 hours, or 44 days.
The capital has had almost 600 day and night warnings, ranging from a few minutes to an all-night alert which lasted just over 14 hours.
Bromley & District Times, 17th January 1943, page 2
Hull Blitz on Wikipedia