We received below message from Smart:
To our Partners,
Please be informed that there will be an Operational Maintenance activity on November 20 and 21, 2018 which may affect transactions during the service affecting window from 12:30 to 3:00 am only.
Activity Time Start:
November 20, 2018 (12:30 am)
November 21, 2018 (12:30 am)
Activity Time End:
November 20, 2018 (3:00 am)
November 21, 2018 (3:00 am)
Effect: No response/Transaction not processed or Errors
We will post another advisory for update. Thank you for understanding.