Does anyone know what this icon means? [Different Notification icon]

Today when i opened my laptop, the ''Notifications'' icon was little different.
Does anyone know what that means and how i can bring it back to normal?

EDIT: Problem solved. It was the ''Quiet hour'' icon little bug thingy, and fixed it by checking and unchecking it only.
Thanks for all the replies.

It's the Action Center .

sn00ker said:

It's the Action Center .

Why before was like that though?

Have you hovered over it? Right clicked on it?

I think he's referring to the o with the dash in it, which is not always there:



I've seen it, too. No clue what it means, though.

EDIT
Whoops, little late to this one! Disregard..

paulsalter said:

I occasionally get the Quiet Hours symbol on the notification button after a restart, but it only stays there for a couple of seconds if that

if its stuck with the little '-' on it try toggling Quiet Hours On then Off

Oh it worked, thanks a lot.
I think it must got stucked from last night that i forgot laptop open and propably went into that mode or something.

kouzou said:

Why before was like that though?

Just like in your first post if you click on any of those squares it will turn the squares On or Off . If you click them all off it will be like pic in this post