What time does the rollover occur?

The rollover occurs daily at 23:59-00:00 GMT (11:59-12:00 AEDT). 

All FX Daily 00:00-23:59 (Monday Open 00:00, Friday Close 23:59) 

Metals Daily 01:00-23:59 (Monday Open 01:00, Friday Close 23:59) 

You will get charged 3 days Swap rates on Wednesdays.