It can be as little as 24 hours (3 full cycles, 6 half-cycles). If you "ACCEPT" at 10:59AM EST on Monday, the trade will process during the PM1 cycle (~11AM EST Tuesday) the next day. If you accept the trade at 11:01 AM EST on Monday, the trade will process at ~7PM, during the PM2 cycle. That would be 4 full cycles and 8 half cycles.
Hope that clarifies schedule1's answer to an unnecessary level of detail.