What do you mean? Its clearly stated in the in game calendar AND in the announcement thread when the Chronoportal event ends.
Missed the calendar statement as the "ending" is published at the beginning, not the end. And if you scroll over all the little icons in the calendar, they don't say anything about what the heck they're supposed to portray. And the ending of the event is buried in a wall of text at the end of the announcement. Just a thought, but when put the start and end of an event in the same sentence at the beginning of the announcement when your announcement is quite large. And it could even be put in the MOTD. I know that's a huge amount of work; I mean it's Thursday or Friday and I enjoy reading about in game downtime for patching still up for days after it's already happened. No excuse, my bad. It was published, but hardly stuck out. A number of people commented about the portals disappearing and what happened.
I always forget about the in game calendar and go by what the official forum says. Also watch discord in case something changes.
ALL events on the calendar show the start day / time and the end day / time according to YOUR time zone when you mouse over the event's name. It has always been this way. During the two (2) weeks of the event, you could have asked in general chat, a friend, a guildmate, etc. or check the News and Announcements thread as they post here for each event with information.
