Stacked Graph of Dates

Please can someone please offer some advice. I wish to plot a Stacked column graph of dates work is completed. Several peoples names along the bottom and dates up the side. The stack shall be broken into 6 steps, each step denoted by the date it was completed.
I would also like a marker at the top of each stack indicating the deadline date.

I’m working from a large table of dates.

Any advice or suggestions would be greatly appreciated.

Regards

Jago

Not one person can suggest how I plot the dates work was completed? Pivot table etc....