Shift Premium Calculation

Hi Experts,

We are implementing Negative Time. As per WSR if an employee works in B or C shift he is eligible for shift premium.We are doing this  through 2010(no of days)  and T511k (rate) through PCR

Now, will it be possible to calculate directly..i.e automatically no. of days from IT0007 instead of maintaining in 2010.                                                       Because to maintain No of shift days for all employees daily ( which is his WSR) will be a big task for user.

Thanks in Advance.