March or thereabouts, according to
black card T&C: (I assume the same for the other non-CIBC black cards)
CIBC Aeroplan Visa Infinite Privilege Card primary cardholders who also hold Aeroplan Elite Status will be able to roll over up to a maximum of 50 eUpgrade Credits received in the prior status year to the next benefit year. eUpgrade Credits issued on a promotional basis, as well as those already rolled over from a previous benefit year, are not eligible for this benefit. Rollover eUpgrade Credits will be deposited directly into the member's Aeroplan account no later than March 30 of any given year, provided the member holds Aeroplan Elite Status at that time, and held Aeroplan Elite Status in the previous benefit year. If your CIBC Aeroplan credit card account is not in Good Standing, or if it is closed, regardless of reason for closure or if the CIBC Aeroplan credit card product is changed to a different product, any unused, rolled over eUpgrade Credits will be forfeited and removed from the member’s eUpgrade account. Benefit is only available to primary cardholders and does not apply to authorized users. Where a primary cardholder is eligible to roll over eUpgrade Credits under another Aeroplan credit card, the total cumulative roll over of all eUpgrade Credits cannot exceed the maximum of 50 eUpgrade Credits.