It's getting dark

[ROBINDESBOIS]

It´s getting dark = está anocheciendo
what about está amaneciendo = it´s getting bright ???? Or just it´s daylight or the day is starting?

[ROBINDESBOIS]

It´s getting light, I saw it in the dic.

[EmpanadaRica]

To dawn
Although this also means to (sometimes gradually) understand.
' Eventually it dawned on me that he wasn't going to help me at all'.
' Listening to the wolves howling in the woods, it dawned on us that we were not safe and needed to find shelter for the night'.

[poli]

Besides dawn which when used literally means el amanecer, we use sunrise or sun up.

[Tomisimo]

Está amaneciendo.
It's getting light.
The sun's coming up.
It's dawning.