Sony SGPT11 - Manual (Page 107)

Note
When you share the schedule on Google calendar, choose the people with whom you share it very carefully to prevent your
schedule from being disclosed to undesired users.
If your calendar is not synced with Google calendar automatically, tap [ Settings] followed by [ Accounts & sync], and
check whether [Auto-sync] is enabled or not.
If your calendar is set to sync with Google calendar automatically and you change the schedule on a computer or other devices,
your tablet device will connect with Google calendar automatically. This may cause unexpected communications charge.