Healthscope time in lieu

I work as a registered nurse in a hospital run by Healthscope. Is there a time limit to taking time off instead of being paid overtime? 

Under Clause 19(xiii) of the Healthscope Group – NSWNMA/ANMF – NSW Nurses and Midwives’ – Enterprise Agreement 2015–2019, time off in lieu of overtime needs to be taken within six months. Where this proves impossible, it is to be paid out at the appropriate overtime rate based on the rates of pay applying at the time payment is made.