On 23.11 (Tuesday), between 10:00 and 15:00 (CET), there will be a maintenance to update the version of the game and prepare it for the merge. During the maintenance, servers will be offline during a couple of minutes. Also, paid account transferred and IP sharing link will be deactivated. Paid account transfer will be activate after merge, IP sharing not.
Merge itself, will start on 24.11 (Wednesday) at 12:00. This means that it's when the option for players to chose the target will be available and will last for 2 weeks.