There is a moment in the morning, in summer, before the sun heaves himself up over the horizon, that is quite magical.
Many people living today never experience this time. Locked away under the tyrany of the alarm clock, and the so called fredom of electric light, they happily sleep through it, secure in the knowledge that they can control their days.
Living on the farm in Romania, I usually wake with the light - frequently there is so much noise from the birds (a dawn chorus is much more than a gentle twitter - it is loud, it is agressive, it is testosterone in full drive) you can't help it. Or the dog gets into full barking mode as the village hounds respond to the first movements of the people down there in the valley.
On the days it is cloudless, there is a distict line moves across the great arch of the sky - it isn't blue, it is a sort of grey white. The stars go out (or fade into the lightening), the moon either holds its own - or isn't there at all.
Always it takes forever - there is an anxiety: Knowledge that the sun will rise - but that rise is agony - tearing itself from its bed almost.
Shakespeare hasn't got a totally clear sky though - there are clouds, ready to be checkered and to fleck. There will be a glorious sunrise - the colours will briefly flash and the sense of awe you get from its magnificence unmatched by anything else in the daily cycle. There is a difference from the sunset - There is a shift from light to dark, an ultimate sinking (good after a day of labour); now is a shift from dark to light - uplifting and inspiring. Energy is coming.
But there is also the English adage to consider: Red sky at night, shepherd's delight, red sky in the morning, shepherd's warning.
The sky goes red when there are rain clouds coming from the east.
I think Shakespeare is tuning into all this with these four lines.
Too often they are treated as just decoration or just a time indicator for the audience to know when it is. Simple mechanics. But I believe his audience associated very quickly with their reality of the natural world.
We are moving from the time of night - with its dreams and confusions, to day. But there are clouds on the horizon.