You need to look at the first notice day - not the last trading day. The first notice day is the first day that a buyer of a futures contract can be called upon to take delivery. The first notice day is often around 4 weeks before the last trading day.
For example mini-Gold June contract, first notice day is 30th May, last trading day is 26th June.
IB Rules:
For long positions not settled in cash, customer agrees to roll forward or close-out the position by offset three (3) business days prior to the exchange-specified first notice day (the long "Close-Out Deadline"). For short positions not settled in cash, customer agrees to roll forward or close-out the position by offset three (3) business days prior to the exchange-specified last trade day (the short "Close-Out Deadline"). It is Customer's responsibility to make itself aware of the "Close-out Deadline". If customer has not closed out any position in a futures contract not settled in cash by the "Close-Out Deadline", IB has the right to liquidate customer's position in the expiring contract.
For example mini-Gold June contract, first notice day is 30th May, last trading day is 26th June.
IB Rules:
For long positions not settled in cash, customer agrees to roll forward or close-out the position by offset three (3) business days prior to the exchange-specified first notice day (the long "Close-Out Deadline"). For short positions not settled in cash, customer agrees to roll forward or close-out the position by offset three (3) business days prior to the exchange-specified last trade day (the short "Close-Out Deadline"). It is Customer's responsibility to make itself aware of the "Close-out Deadline". If customer has not closed out any position in a futures contract not settled in cash by the "Close-Out Deadline", IB has the right to liquidate customer's position in the expiring contract.