The following graphs are extracted from the same data base: just a single point for each opening day, also in the case of long openings.

They show the peaking time of the opening, but also how the openings are distributed through the months, with reference to the sunrise line on the eastern point of the path. Of course, in these crowded  graphs it’s quite hard to detect any influence of the sunspot cycle!

Due to graphical constrains all the openings before 24.00z towards the West direction are put just above the 0.00z line.