Hi Pooja ,
Many companies whose employees working at client locations follow a timesheet system for attendence on a monthly basis.
It is an MS- Excell sheet with details of Employee on the first sheet and remaining sheets their attendence for particular month.(Each sheet for Each month.)
Or
at the beginning rows in each sheet mention the employee details and remaining roas their attendence( Date,Day,Present/Absent,Hours of Work, Shift type etc on each column) Here also each sheet for Each month.
Ask them to send this sheet to their reporting person @the client and ask him to mark his approval after checking the records of their attendence which is mainitaned at his end and after then forward to u.
Make month end the date of submissios for the same after getting necessary approval and incase they are not sending it, it means they have not worked for that month.Its as simple as that.
But u have to communicate the procedure & the outcome, if not followed,to the employees well in advance.
This will be a better solution instead of trying to figure out their attendence on a daily basis which will be hectic since they are not present in the location where u sit.
Revert if u require any more details reg d same.
Sandeep