Glamsterdam Has a Date: Ethereum Forks Sepolia on September 28, 2026

Glamsterdam has a date for the first time. On September 28, 2026 at 14:44:48 UTC, the next major upgrade to Ethereum is due to activate on the Sepolia test network. The number comes from the minutes of the developer call held on August 20, 2026, it is pinned down to the exact epoch and slot, and six client teams confirmed it in the session chat without dissent. Two qualifications belong in the same breath, otherwise a schedule turns into a promise. First, the date is provisional: the minutes note explicitly that the decision was deferred to the next call. Second, it applies to a test network and nowhere near a main network. There is still no date for mainnet, and the figures circulating online for it have not added up since August 20. This piece shows you where the date comes from, how to recalculate it yourself, what could still overturn it and what changes for you as an ETH holder. The background to the content itself, meaning which changes Glamsterdam actually contains and how the selection for the following upgrade works, sits in our piece Ethereum upgrade after Glamsterdam: what is actually decided in Hegotá. This one is about the calendar. When Is Glamsterdam Coming? The Firs...