When try to schedule an event on Team Calendar on date 18 of October, the following error came up:
Error(s) occurred.

Illegal instant due to time zone offset transition (daylight savings time 'gap'): 2015-10-18T03:00:00.000 (America/Sao_Paulo)

Even with the correct timezone setup on the user profile we keep facing the error message. This looks like to be related to the daylight savings which will start at 18 of October.
http://www.timeanddate.com/time/change/brazil/brasilia