"TIME values may range from '-838:59:59' to '838:59:59'". Oooh Kaaay… that’s an oddly specific range, but I’m sure there has to be a technical reason for it. 839 hours is 34.958(3) days, and the whole range spans exactly 6040798 seconds.
It's been 20 years since MySQL Replication was introduced in MySQL 3.23.15 (Released in May 2000). Since then, virtually every MySQL Database deployment in production has been using Replication in order to achieve high availability, disaster recovery, read scale out and various other purposes.