Flexible work arrangements can include changes to your start and finish times. Flexibility in the workplace is so important and very much valued by employees.
There are ways that employees can request flexible work arrangments, assuming they meet the criteria (see Fair Work Australia https://www.fairwork.gov.au/employee-entitlements/flexibility-in-the-workplace/flexible-working-arrangements).
You may be able to set your arrangements by writing to the employer, explaining your reasons for the requested change and what changes you would like made.