Hedera will be upgrading the Mainnet to v0.9.0 (release notes:
https://hedera.io/release-notes) on Thursday, Dec 3rd 2020 at 17:00 UTC. v0.9.0 includes Hedera API deprecations which might require action (
https://hedera.com/blog/changes-to-hedera-api-hapi-for-v0-8-0-and-v0-9-0). In addition, Mainnet node 4 (0.0.7) and Mainnet node 6 (0.0.9) will undergo maintenance then be brought back online. We will also add an additional node, UCL's node 13 (0.0.16) bringing the total node count to 14/14.