When new annotation created in PIWIK, it propose wrong date. It should be today because it is probably correct guess in over 80% cases. I do use a lot of annotation for every major milestone in either tracked web or PIWIK itself, so it is annoying, because you have to select to correct date form calendar box.
Moving bugs to our current milestone to make the backlog more realistic.
In 757c78ea4a708d24c8264e4fc1ee94bdc9a700da: fixes #4888 use today as default date for new annotations