Welcome to the forum.
As you've found, there are thousands of ways to make a calendar, but typically, none of them do exactly what you want!
As far as entering the days of the week, you could just enter "Sunday" in one cell, then select the cell, click on the bottom right corner, and drag it to the right, and Excel will fill in the days for you. You could use a formula, which I've shown below.
Excel 2012
| A | B | C | D | E | F | G | H | I |
---|
Sunday | Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | | | |
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |
<colgroup><col style="width: 25pxpx"><col><col><col><col><col><col><col><col><col></colgroup><thead>
</thead><tbody>
[TD="align: center"]1[/TD]
[TD="align: right"]12/1/2017[/TD]
[TD="align: right"][/TD]
[TD="align: center"]2[/TD]
[TD="align: right"][/TD]
[TD="align: right"][/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]2[/TD]
[TD="align: center"]3[/TD]
[TD="align: right"][/TD]
[TD="align: right"][/TD]
[TD="align: right"]3[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]5[/TD]
[TD="align: right"]6[/TD]
[TD="align: right"]7[/TD]
[TD="align: right"]8[/TD]
[TD="align: right"]9[/TD]
[TD="align: center"]4[/TD]
[TD="align: right"][/TD]
[TD="align: right"][/TD]
[TD="align: right"]10[/TD]
[TD="align: right"]11[/TD]
[TD="align: right"]12[/TD]
[TD="align: right"]13[/TD]
[TD="align: right"]14[/TD]
[TD="align: right"]15[/TD]
[TD="align: right"]16[/TD]
[TD="align: center"]5[/TD]
[TD="align: right"][/TD]
[TD="align: right"][/TD]
[TD="align: right"]17[/TD]
[TD="align: right"]18[/TD]
[TD="align: right"]19[/TD]
[TD="align: right"]20[/TD]
[TD="align: right"]21[/TD]
[TD="align: right"]22[/TD]
[TD="align: right"]23[/TD]
[TD="align: center"]6[/TD]
[TD="align: right"][/TD]
[TD="align: right"][/TD]
[TD="align: right"]24[/TD]
[TD="align: right"]25[/TD]
[TD="align: right"]26[/TD]
[TD="align: right"]27[/TD]
[TD="align: right"]28[/TD]
[TD="align: right"]29[/TD]
[TD="align: right"]30[/TD]
[TD="align: center"]7[/TD]
[TD="align: right"][/TD]
[TD="align: right"][/TD]
[TD="align: right"]31[/TD]
</tbody>
Sheet1
[TABLE="width: 85%"]
<tbody>[TR]
[TD]
Worksheet Formulas[TABLE="width: 100%"]
<thead>[TR="bgcolor: [URL=https://www.mrexcel.com/forum/usertag.php?do=list&action=hash&hash=DAE7F5]#DAE7F5[/URL] "]
[TH="width: 10px"]Cell[/TH]
[TH="align: left"]Formula[/TH]
[/TR]
</thead><tbody>[TR]
[TH="width: 10px, bgcolor: [URL=https://www.mrexcel.com/forum/usertag.php?do=list&action=hash&hash=DAE7F5]#DAE7F5[/URL] "]C1[/TH]
[TD="align: left"]=TEXT(
"2017-12-"&COLUMNS($C1:C1)+2,"dddd")[/TD]
[/TR]
</tbody>[/TABLE]
[/TD]
[/TR]
</tbody>[/TABLE]
[TABLE="width: 85%"]
<tbody>[TR]
[TD]
Array Formulas[TABLE="width: 100%"]
<thead>[TR="bgcolor: [URL=https://www.mrexcel.com/forum/usertag.php?do=list&action=hash&hash=DAE7F5]#DAE7F5[/URL] "]
[TH="width: 10px"]Cell[/TH]
[TH="align: left"]Formula[/TH]
[/TR]
</thead><tbody>[TR]
[TH="width: 10px, bgcolor: [URL=https://www.mrexcel.com/forum/usertag.php?do=list&action=hash&hash=DAE7F5]#DAE7F5[/URL] "]C2:I7[/TH]
[TD="align: left"]{=IFERROR(
DAY(TEXT(A1,"yyyy-mm-")&{2,3,4,5,6,7,8}+{0;7;14;21;28;35}-WEEKDAY(A1)),"")}[/TD]
[/TR]
</tbody>[/TABLE]
Entered with Ctrl+Shift+Enter. If entered correctly, Excel will surround with curly braces {}.
Note: Do not try and enter the {} manually yourself[/TD]
[/TR]
</tbody>[/TABLE]
Put the formula in C1, then drag to the right. As far as the dates, put the first day of the month you want in A1. Now select C2:I7 (or any other 7X6 range). With the whole range still selected, enter the C2 formula, then confirm it by pressing Control+Shift+Enter, instead of just enter. Now the dates will fill the grid when you change the date in A1. You can format the grid as you like, with gridlines, or fonts, or colors. You could also put individual formulas in the cells if you want, depending on what else you want to do with the calendar.
Let us know if this helps!