Format Date "Start" and "End" Columns

Right now the format shows as 2015-12-21. I am looking to make this more friendly. Something along the lines of “December 21”. Thoughts on if this is possible? I might have to actually ditch this software because of finicky clients if this is not the case :(

Im also looking to show “AM” and “PM” without the time since we don’t work in hourly increments. We only do 1/2 day increments or more.

My thought was to add a new column that allows me to add in any information but it looks like there is no option to add a comments column. There is a notes column but it adds notes underneath.

The columns rely on the computer’s System Preferences for short date format. You can customize it, but it will affect lots of other things on your computer as well.

Not quite what you’re asking, but for the gantt headers there is customization available directly in the app: