Prior to the Hoodi postponement, Ethereum developers were considering December 1, December 8, and December 9, 2026, as potential mainnet activation dates.

From the articleEthereum Delays Glamsterdam Upgrade After Security Researchers Flag RisksAlso in Ethereum Glamsterdam Delay: ChainSecurity Flags 13 Contracts Where Failures Turn Permanent, Ethereum's long-awaited Glamsterdam upgrade hits another roadblock as 13 security risks emerge