As for combining conditions you can consolidate some current conditions into one without it being confusing to users. Combining condition ‘Day and Night’ and ‘Time’ into one can easily be done. Re-name it to ‘Day/night and Time’. When you show the clock to set the times, just add a ‘Sunset’ and ‘Sunrise’ button under the clock. So you can either select a specific time or just go for ‘Sunset’ or ‘Sunrise’.
This way the user can mix day/night with time setup. F.e. tell a switch to activate a ‘daytime’ scene starting after ‘Sunrise’ and use a ‘nighttime’ scene starting after 19:00.
In case it helps to understand where I come from; this last example scenario is useful for me in the children bedrooms. In the morning the brighter ‘daytime’ scene can be activated once the sun is up outside. In the evening the more dimming ‘nighttime’ scene should start after 19:00 because that is bedtime for them and I need more dimming light with their curtains being closed even if the sun is still shining at 19:00 (as is the case in summertime).