Naming new tabs with dates from the cells

Hi Guys,

I am trying to name the new worksheet tabs using VBA; I found this code (Rondebruin's) which works perfectly but it names the tabs with names, but I want to name them with the (exit) dates, preferably "mmm dd" format,
and if the sheet exists append the fields else create new worksheet to update the data. I tried to modify the code without any success as my knowledge of VBA is limited. I'll appreciate any help. Thank you.