Temporarily put OS X notifications in "do not disturb" mode?

A person will be sitting next to me, working together with me on my Mac, and I would like the make sure none of my personal notifications appear during that time. I would not want to lose my carefully chosen notification settings though so a "temporarily do not disturb me" would be perfect.

Note: this is for OS X, not iOS...

Solution 1:

You can option click on the notification center icon in the menu to quickly enable or disable alerts and banners.

(Notifications are temporarily disabled and will be automatically reenabled the next day)

Solution 2:

Make sure that Notifications are visible and then scroll down (I pull down with 2 fingers with natural scrolling on my trackpad), a new option Show Alerts and Banners with a toggle switch appears at the top, turn that off.

When you want them back on, repeat the process and turn it back on.