there is a lot of overlap in the times and of course in winter there will be less sunhours because of the lower trajectory of the sun..
In summer my 'morning sun' is more or less from 9.30 a.m. - 2.30 p.m. , midday sun is from 11.30 a.m. - 4.30 p.m. and afternoon sun is from 2 a.m. - 7.30 p.m.
I've had DL's in all borders this summer, and they all did absolutely fabulous!
I have 2 DL's that I planted last year and 22 that I planted this April / May.
6 of the new ones didn't flower (very small spiders, not in 1 particular border), but I had a total of over 500 flowers from the others
White Temptation is still blooming and 2 of the new ones are growing new scapes (rebloom)
I know that that's nothing compared to your gardens
, but for a newbie like me more than 2 months of blooming DL's is quite an experience
Apart from them blooming and thriving again next year, I am worrying about, if we have cold nights in winter, with temps below 0, will the morning sun do damage to the (semi-)evergreens?