If an employee has a change of salary on their record you will not be able to create a sickness that spans over the effective date of the pay change.
To resolve this, you will need to create two separate sicknesses. The first will need to end before the effective date of the pay change and the second will need to start on the effective date.
For example: If an employee's pay will change on September 1st, the first sickness needs to end on August 31st and the second needs to start on September 1st.
Check pay change date
Search for the employee and go to their profile.
Click Payroll, then Pay.
Click Pay History.
Review the salary lines to see which pay change date is included within the start and end dates of the sickness.
Add the sickness
Search for the employee and go to their profile.
Click Absence, then Sickness.
Click Add Sickness.
Create the first sickness and end it before the pay change date.
Click the sickness and make sure it's closed by adding a Last Day of Sickness.
Click Add Sickness again.
Create the second sickness which starts on the pay change date.