corresponding dates/rows on worksheets must not have same names in them

[reeves]

Hi, thanks in advance for any help that can be given. I've attached an image of something that may help me make more sense.

What I'm doing is making 3 different lists of responsibilities that people will check on a bulletin board. Their names will be listed on a row corresponding to a particular date. The individuals name cannot appear on the same date on more than one of the lists although they will appear on more than one list just not on the same date as stated above.

How can I accomplish this?

I hope I've made enough sense to receive some assistance and thank you for your help.

p.s. I would also love a way of making the sheet/workbook auto sort the names every month. Suggestions?