Need database for storing shift roster and at end of month can check employee attendance?

Please see https://www.experts-exchange.com/questions/28058187/Tracking-membership-and-attendance-in-Access-Database.html for a good discussion including Patrick Matthews who excels at Access (pun intended).  I think the design fits your needs.  A member is instead an employee, sessions are valid work dates (you could have a different table of shifts unless I am reading correctly on the shift changes then you could have that be a field on your work date*), then your attendance is the unique association of shift/date and employee.

*In many systems, there is a date table with a flag that says valid work day (or the inverse flags weekends/holidays as non-work days).  In your case, you can have this be a column with shift codes A, B, C, G by specific date if only one shift is valid for specific date.  Then the attendance table just uses the PK of the dates table (e.g., DateID) and the PK of the employees table (e.g., EmplID) as a combo unique key.

Here is the gist of Patrick's solution with the changes I said above:

tblEmployees
----------------------------
EmplID (PK)
EmplFName
EmpLName
...

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tblShifts
----------------------------
ShiftID (PK)
ShiftCode
ShiftDate

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Where ShiftCode is A, B, C ... and appropriate calendar date.  Again if you can have more than one shift on a day, it probably is better to just have this table be a list of dates and whether or not they are valid work days.

tblAttendance
----------------------------
AttendID (PK)
ShiftID (FK) 
EmplID (FK)

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If ShiftCode not in the dates table, you can add it here.  If an employee can be in more than one shift a day, then add ShiftCode to the unique index with ShiftID and EmplID so it will let you have duplicates of the employee for a given shift as long as they clock into a different shift code.  I hope that makes sense.