Bump.

I have the same issue. Shown date in the calendar is one day to early.
Has anybody found a solution ?

Which version of Joomla!/ K2 are you using? Also which version of PHP is your server running and finally which other extensions are you using?

I'm running Joomla 3.3.6, Php 5.4.30, K2 2.6.9.
Other extensions are: RSform Pro, JCE editor. No extra plugins or modules.

As you can see in my screenshot (imgur.com/VkiNiPq) the dates in the calendar are one day before the actual K2 item's date.
I'm in the GMT+1 timezone, server time is also GMT+1.

Which version of PHP are you using?
www.inmotionhosting.com/support/edu/joomla-25/version/which-version-of-php

PHP Version: 5.4.30 (see previous reply)

@Ronny Van Der Borght

Is there a link to the page with the issue?

Sure: salario.be/dev/sociale-kalender

What's the creation date on the item edit screen? Do you have any template overrides? If so, try to disable them for a while. Is this a multilingual site?

No multilingual site. Just one font-end language 'Dutch' , backend languages are Dutch and English (default, required).
For the k2 item 'Bedrijfsvoorheffing" the creation date is 2015-01-15 00:00:00 (shown in K2 items on the backend), but on the calendar it shows up on 2015-01-14, in the K2 category (left to the calendar) is shows as 2015-01-15 (15 januari, 2015).

I have tried the default Joomla template Isis (imgur.com/tO5c3Fv): same issue. So this is not caused by a template override.

There might be overrides also in the core component folder. So check this also. Finally, i suggest to enable Joomla! debugger and look out for the queries who start like "SELECT COUNT(*) FROM #__k2_items WHERE YEAR(created)" . This is a simple count query. If there are no items in the specific date it should return no results.