For now Samsung confirmed only one date connected with Galaxy Note 8 - it's 23th of August, when Samsung's Unpacked event will take place and company plans to officially present their new phone there. Usually Samsung begins sell of their new phones around two months after official presentation, but this time situation may be different.
Some people say that Samsung Galaxy Note 8 may come to shops even day after phone's presentation on Samsung's Unpacked. However, it's unclear if 24th of August is the date connected with sale only in United States, or it concerns about whole world. How we can read on Reddit, this rumor was confirmed "through both Verizon and Samsung channels". Just for the record: previously it was rumored that Galaxy Note 8 will be available in shops since 15th of September. We don't know which date will be correct, and we just have to wait for 23th of August with solving this problem.