Help with Formula to Keep Running Total of Accrued Vacation and Sick Time

Hello,

I have started a spreadsheet (attached) which will be for tracking sick and vacation time used and keep running totals for each as well. The spreadsheet should be useable by everyone in the business so I want the formulas to refer to cells L7-L9 and print the running totals in cells C2 & C4.

Sick Hours accrue at 4.6 hours per pay period
Vacation Hours accrue as follows: 0-7 years service = 3.1 hr/pay, 8-14yrs = 4.6hr/pay, 15-24yrs = 6.2hr/pay, and 25+yrs = 7.7hr/pay

This spreadsheet needs to know what the date is currently, and add the appropriate amount of sick and vacation hours accrued and subtract any hours used in each category.

To further clarify, if I started the year with 737.3hrs sick time and it is today (4/3/12), my sick hour balance printed in cell C4 would be 737.3hr + (4.6 hrs accrued per period * 6 periods) - 80 sick hours used thus far = 684.9 hours

If you can offer me help with the formulas I would greatly appreciate it. Thank you for taking the time to help.

Best Regards,

Joe