Your 3 formulas are:

Start Calendar Week = IIf(DatePart("ww",[Start],1,2)=53,Year([Start])-1 & " Week " & DatePart("ww",[Start],1,2),Year([Start]) & " Week " & DatePart("ww",[Start],1,2))

Finish Calendar Week = IIf(DatePart("ww",[Finish],1,2)=53,Year([Finish])-1 & " Week " & DatePart("ww",[Finish],1,2),Year([Finish]) & " Week " & DatePart("ww",[Finish],1,2))

Deadline Calendar Week = IIf(DatePart("ww",[Deadline],1,2)=53,Year([Deadline])-1 & " Week " & DatePart("ww",[Deadline],1,2),Year([Deadline]) & " Week " & DatePart("ww",[Deadline],1,2))

Note that for tasks without a deadline date, there will be an error.