The rollover_date is the date on which an account was rolled-over [See roll over.] For a term deposit, this would be the date at which the deposit was rolled to another term. For a notice account, where notice has been given, this would be the date on which the notice was given. If notice has not yet been given, it would be the current business date.  It is in date-time format in accordance with the ISO 8601 standard (YYYY-MM-DDTHH:MM:SSZ)