At sunrise, the sky isn't actually up in the sky yet. Twilight occurs before sunrise, then at sunrise the leading part of the sun crosses the horizon. But, the sky isn't bright yet. It takes some time for the sky to be blue again.

Then, at the closing of the day, the sky darkens before twilight, then sunset.

Basically, there is a narrower time when the sky is bright and blue, rather than being the time between sunrise and evening twilight. Is there a name for these times, or at least a name for its boundaries?

Edit: Here's a picture to better point out what I mean:

enter image description here

The shaded part after sunrise I label 1 is the part after sunrise, when the sky is still dark but the sun is out in the sky (here's an image).

The shaded part just before sunset I label 2 is the part when the sky is already darkening, but it's not yet sunset as the sun hasn't set below the horizon (an image again).

The large portion of the day I label 3 would be the part when the sky is blue and bright, the term for which I'm asking for, if it exists (here's an image).

  • 1
    $\begingroup$ This question appears to be off-topic because it does not seem to be about physics. $\endgroup$
    – Dilaton
    Aug 6 '13 at 11:42
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    $\begingroup$ After sunrise when the sky is bright? I call it day $\endgroup$
    – Jim
    Aug 6 '13 at 13:25
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    $\begingroup$ @Dilaton this is the physics and astronomy stack exchange. It's on topic. $\endgroup$
    – Nathaniel
    Aug 6 '13 at 14:08
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    $\begingroup$ @Dilaton It seemed to me to be a question about astronomical terminology. "Everyday physics" questions are on topic here (and some of them are quite good), so I think "everyday astronomy" ones should be as well :) $\endgroup$
    – Nathaniel
    Aug 6 '13 at 14:24
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    $\begingroup$ I'm voting to close this question as off-topic because it's about terminology, not physics. $\endgroup$ Apr 8 '18 at 19:59

There is daylight, civil twilight, nautical twilight and astronomical twighlight. Each defined by the position of the sun relative to the horizon.

The wikipedia article seems unusually helpful. With diagrams as well.

  • $\begingroup$ The twilights happen before sunrise, so basically at the end of the very last twilight, is sunrise. At sunrise, the sky isn't blue or bright yet. The wikipedia article doesnt mention a "boundary" in the day after sunrise when the sky does become blue. Maybe there just isnt a word for it. $\endgroup$ Aug 6 '13 at 12:46

The time after the Sunrise is known as Morn.

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    $\begingroup$ Consider including a reference. We like those here! Cheers! $\endgroup$ Apr 8 '18 at 19:59

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