You will need to set up special leave entitlement rules (unless a standard entitlement applies), enter any Opening Balances and check your figures.
Ensure that they have the correct leave entitlement code on their Timesheet Template.
Record SICK on the person's timesheet, using either the timesheet entry or the Leave History page.
Note that when recording Sick leave you may be required to enter the number of days to deduct off the person's balance, in addition to the number of hours to pay. (This extra information is required for part time staff where details of their exact working patterns aren't recorded).
To record Unpaid Sick Leave, use SICK-LWOP instead. (Alternatively, you could simply reduce the number of Paid hours and not record any leave. Refer to SICK-LWOP for more details on these options).
These will occur at the appropriate times, giving a new entitlement and updating balances.