Time recording and billing

We have a client who work on a number of contracts. They employ 100/200 staff who are charged out at agreed rates for normal and overtime. They work from dailt time attendance records maintained by foremen which typically will cover 20/30 employees. There will be various grades of staff. Currently the data is collated on spreadsheets and invoiced fortnightly to the main contractor with the spreadsheet schedules of time worked etc. Does anyone know of a turnkey product that would cope with this or do we need to use a database? Thanks in advance for any help
Bob Clarke