Data1969=GroupBy[Most[DateRange[DateObject[{1969,1,1}],DateObject[{1+1969,1,1}]]],DateValue[#,"MonthName"]&];
InitialOffset1969=QuantityMagnitude[DateDifference[PreviousDate[DateObject[{1969,1,1}],Sunday],DateObject[{1969,1,1}]]];
MonthLengths1969=Length/@Values[Data1969];
Offsets1969=Offsets[7,InitialOffset1969,MonthLengths1969];
MonthNames1969=Keys@Data1969;

YearBanner1969=BannerGrid[{0,0},{{1,1},{0,0}},<|"border"->"X"|>,DataGrid[{1,1},{1,1},{{1,1},{5,5}},<||>,#]&,13,"1969"];

MonthGrids1969=
  With[
    {monthNameGridder=DataGrid[{1,Length@#},{0,1},{{1,1},{0,0}},<||>,ToUpperCase@#]&,
     dayNameGridder=DataGrid[{1},{2},{0,0},{{0,0},{0,0}},<|"alignment"->{0,-1}|>,#]&,
     dayGridder=DataGrid[{1},{2},{0,0},{{0,0},{0,0}},<|"alignment"->{-1,1}|>,#]&},
    With[
      {monthGridder=
         MonthGrid[{0,0},{{0,0},{0,0}},<||>,monthNameGridder,#1,
         {0,1},{{0,0},{0,0}},<||>,dayNameGridder,WeekdayNames[],
         dayGridder,#2,#3]&},
      MapThread[monthGridder,{MonthNames1969,Offsets1969,Map[ToString,Range/@MonthLengths1969,{2}]}]]];

MonthsGrid1969=DataGrid[{3,4},{1,4},{{0,0},{0,0}},<||>,MonthGrids1969];

DataGrid[{2,1},{2,0},{{0,0},{0,0}},<||>,{YearBanner1969,MonthsGrid1969}]//AsString