EJB Timer is not fired during the ambiguous hour during the switch from summer to winter times ---------------------------------------------------------------------------------------------- Key: WFLY-9537 URL: https://issues.jboss.org/browse/WFLY-9537 Project: WildFly Issue Type: Bug Components: EJB Affects Versions: 11.0.0.Final Environment: Here CEST -> CET change from 2017 Nov. 29 2:00 CEST .... 2017 Nov. 29 2:00 CET Reporter: Wolf-Dieter Fink Assignee: Eduardo Martins If a calendar timer has a schedule less than an hour, and should fire during the DST switch it is expected to be fired like this: Asume : @Schedule(hour="*", minute="5/15", timezone="Europe/Berlin") 2017 Nov. 29 1:50 CEST 2017 Nov. 29 2:05 CEST 2017 Nov. 29 2:20 CEST 2017 Nov. 29 2:35 CEST 2017 Nov. 29 2:50 CEST 2017 Nov. 29 2:05 CET But the timer is fired like this: 2017 Nov. 29 1:50 CEST 2017 Nov. 29 2:05 CET All events within that hour are lost!