i think its too much work, adding all real dates. i would just add random flights with a group size related to the year. in 1939 add 5 raids, in 1940 15 and so on. in 1945 it might be 50 raids. even that would be work enough! what do you think?
otherwise here is a list of attacks on the uboat harbours
https://en.wikipedia.org/wiki/Submar...bing_offensive
attacks on german cities
https://en.wikipedia.org/wiki/List_o...ttle_of_Europe