As salaam alaykoum,
could you please include also the calculation method used in Germany as developed by dr. Hawari which were presented to the Islamic world league in the 80s regarding the late time of ishaa and early fair in summer.?
you can find the prayer times developed on the website of Aachen Islamic center www.izaachen.de
the method is to take the closest city where the signs are observable.
barak Allahu fik