Calendar events are 1 hour shifted in European summer time CEST

There is a bug in calendar, which is effective during CEST - Central european summer time. Event entered in EMC is shown 1 hour shifted in other clients (mobile, webmail, etc.)
The other way round, event entered in mobile is created correctly and is shown right with the same start time in EMC. (see screenshot)
This bug relates to unsuitable value DTSTART when EMC creates event.
Has anyone encountered this issue?