Cuba Maintains +5 UTC Offset Through November 2027

Cuba announced continuation of its summer time offset through the 2026-2027 winter period. The change eliminates the biannual transition that normally occurs on the first Sunday in November. Official notices list no reversion date before the 2027 spring adjustment.

Data from prior Cuban DST periods show average evening peak load reductions of 1.8 percent in the national grid according to 2019-2023 dispatch records. Comparable studies in the United States and Europe report mixed or null net savings once heating and behavioral rebound effects are included. Cuba’s island grid lacks the interties that allow larger systems to shift load across time zones.

Health literature links abrupt clock shifts to measurable increases in myocardial infarction admissions on the days immediately following transitions. Cuba’s decision removes one such shift in 2026. Other jurisdictions including Mexico and most of the European Union have either ended or scheduled the end of seasonal changes citing the same evidence.

Operational impact centers on synchronization with Caribbean aviation schedules and the US Eastern time zone. Airlines and port operators will operate under permanent DST offsets for 13 consecutive months. No public consultation or impact assessment document has been released.