Long summer days mean late nights.
Long summer days can be productive if you need sunshine and skies..but for dusk and night photography the days only mean very late finishes and early starts.
Getting just the right balance of darkening sky and the working lights influencing the scene can be a short window of opportunity. The 'Golden hour'..and 'Blue hour' are often used to describe the changing light from day to night. Getting just the right time to get a night sky and yet still have enought light to contrast the structure against the sky to retain it's shape and form but still dark enough to let the working lights on the building or structure to create the magical pools of light is more an art of observation than science.
Spring and Autumn are often a great time for dramatic skies full of colour as the low sun helps the high level clouds to 'catch fire' but not everyone has time to wait for just the right sunset/sunrise so in the meanwhile it's sleep depravation time.