What is the half-moon symbol in my messages list ?

[iMore Question]

I have the list of txts that I have sent and received.
1 has a half-moon symbol next to it. what does this mean ?

 

[Bigeric23]

Re: what is the half-moon symbol in my messages list ?

This should explain (Do Not Disturb):

https://discussions.apple.com/thread/6575556