Section 252.15  Existing Leave

An employee who is entitled to take paid or unpaid leave (including family, medical, sick, annual, personal, or similar leave) from employment, pursuant to federal, State, or local law, a collective bargaining agreement, or an employment benefits program or plan may elect to substitute any period of that leave for an equivalent period of leave provided under Section 10 of the Act. [820 ILCS 154/15]