Dynamically display selected month missing Days in GridView using C# and VB.Net in ASP.Net

sir i have  have table that hold attendance record of employees of every month

now i wants to show attendance in gridview but problem is that every month days are change for example march has 31 and apirl has 30 and feb has 28 or 29 

i wants fetch record month basis using where clouse in sql  now piont is on week off attendance not marked (so sql table not holds that day data )that means in august 2017 on date 6,13,20,27 was sunday

i wants to show as

name   1 2 3 4 5 7  8 9 10 11 12 14

so wants to add column as with header text as date and cell text as P/A

thank you