we are working hard here in Moodle HQ to deliver Moodle 3.1 to you full of new and amazing features. We are still polishing some of these new features and we do not want to start other pre-release tasks such as community QA cycle and documentation writing before the polishing is finished. Therefore we decided to move the release date by two weeks and instead of planned second Monday of May it will happen on 23rd of May.
As a result the code freeze is also moving by two weeks and will hapen on 18th of April.
Minor releases of stable versions will comply with the regular release schedule and are still expected on May 9.