Given a Chase credit card with SUB of 25,000 miles/points for $3,000 in 3 months and another 25,000 for $6,000 total in 6 months, with 25,000 posted on January 2021 statement and 25,000 posted on May 2021 statement, when would the "past 24 (and/or 48 months)” end? Thank you.