For me where i hunt the first 2 weeks i only hunt the evening hunt (I know i am missing time in the field) but due to heat meat care etc thats what i do and i do pretty good.
If i am hunting the last week and half i usually will hunt mornings and evenings as the weather usually has cooled alot by then, not unusual to have temps at or very close to freezing some nights which keeps the bugs down.
Also it can be really cool to put the woods to bed, sundown can be just as much fun as sunup.