SQL & PL/SQL

Hi ,

I have a PAYMENT table that should be able to handle salary payments for Full time, Part time and Temporary staffing.(let leave out OverTime, sick_leave, Holidays etc).

Full time and Part time are paid monthly worked out from a contractual annual salary while temps are paid weekly for hours worked per week.

Which is the industry standard on most payroll systems to work out a full time employees monthly pay from his annual salary of £35000 on the assumption that he has worked 35 hours per week and that he is not a per hourly-paid employee.

((ANNUAL_SALARY/52)*4)
OR
ANNUAL_SALARY/12

Also taking into consideration that wages are paid on the 28th day of every month.

What if the 28th falls on a weekend, how can this be programmed to fall on the last working day before the last weekend and for the next 10 years or so. Do I really need to incorporate a calender here.

Help me out.

Thanks