Event end date is not correct (timezone issue)

Problem/Motivation

We have issue that event is considered as passed for users with timezones in range +1h ~ +12h.
For example, we have an event with today's end date 10:00 am (UTC).
I'm logged in as user with timezone EEST (Europe/Helsinki) with timeshift +2h.
If I visit an event at 10:30 am (EEST) I can't enroll to event because event it considered as passed for me (but there is 1:30h to it ends).

Steps to reproduce

1. Login as CM+
2. Make UTC as your default timezone (in user settings page)
3. Create a public event that is finished in 1h
4. Login as LU
5. Make EEST (Europe/Helsinki) as your default timezone (in user settings page)
6. Visit an event and try to enroll

Proposed resolution

Fix bug with timezone.

Remaining tasks

n/a

User interface changes

n/a

API changes

n/a

Data model changes

n/a