Timezone: open the side menu, tap Settings, then Timezone, and pick yours. Appointment times are shown in this timezone.
Language: the app is in English for now. Settings > Language (English or Malay) changes a few labels on the Tera AI Voice screen and helps Tera understand your speech. Tera replies in the language you use, so you can talk or write to Tera in Malay or English at any time.