I have a question about tier miles. A friend is silver from 29 Dec 2016 and in his A3 account it says that he needs 15k miles to Gold until 29 Dec - he has silver until Dec 2018. On Dec 22 he has a flight bringing him 10k miles and on Jan 1 another one giving 15k. After Dec 29 does the counter reset, i.e. will he need 24k incl. 4 A3 flights for Gold or do the miles roll-over that he collected within 12 months of a specific date?