Not sure when this happened, but I think it was on a recent dev build. All my show times now say they are airing at 12am. The days are still correct. Just not the times.
Example:
Brooklyn Nine-Nine
12am Jan 4 2015
Beach House
Nevermind…
UTC Air Dates for episodes (Air times on the calendar will be off until our full solution is implemented)
Thanks for posting so I found it easier. 
Exactly i was thinking the same, suddenly all times were different and not correct. Awaiting an update 
Is that an old release note?
It was actually from the banner at the top of the site that said…
Sonarr now connects to TVDB for series and episode information, you will need to upgrade to add new series or refresh existing ones. More details.
When you click on the link it gives a full explanation about Trakt’s own update and how it broke Sonarr. Along with what they did to temporarily fix it.
Here is the important bit that affected me…
The Interim Solution
Sonarr talks directly to TVDB for series information now, which means we’re back in business with a slight loss of functionality (for the moment). The loss of functionality is:
UTC Air Dates for episodes (Air times on the calendar will be off until our full solution is implemented)
TV Rage IDs - new series will not have TV Rage IDs which are used for searching so title based searching will be used, its not perfect, but it will work.
I believe Trakt had their Update/Upgrade last weekend.