Invitation - Times not correct for a single user

Hi all, 

I have an odd case with a meeting where only a single or the participants are getting the meeting to be an hour earlier. (attached is a screenshot from her and the same for me). 

I initially thought it would be summertime vs winter-time or a wrong timezone, but it seems not to be the case as all other invites to her is fine. We're all sitting in the same office, so it's really weird. 

What could be the issue?