For each Account that you spin up an @Hosted account, you can define what timezone your customer is located. This is an important setting as this will ensure that any time based rules that they setup (like in Service Flags) is run correctly.
Navigate: Accounts > List All > Config > Hosted Voice
Within the Hosted Voice Settings, ensure that the Timezone field is setup correctly. This is the timezone that the platform will use when running any time based rules.
Hosted Voice Settings tab with the Timezone field set to Western Australia