Drupal timezone and database
What version of Drupal is this?

It's against best practices to go directly to the database but if you really need to I don't see why you can't query the field's table. What problems are you having? 

When entering data for a field, the data entered is assumed to be in the site's time zone. When the data is saved to the database, it is converted to UTC. When retrieved from the database, the data is converted to the Site's time zone for anonymous users or the User's time zone for logged in users when User-configurable time zones is enabled.

You may wanted to use format_date to convert your time.
See: https://api.drupal.org/api/drupal/includes!common.inc/function/format_date/7

UPDATE:

I don't know what source you time is in, either a timestamp or formatted date/time. In your example you're using  2014-04-28 11:00:00 so lets convert that to a unix timestamp:

  $newdate = new DateTime('2014-04-28 11:00:00 UTC', new DateTimeZone(date_default_timezone_get()));
  $unixts = $newdate-&gt;getTimestamp();
  $siteDate = format_date($unixts, 'small', '', date_default_timezone_get());