Recurring due date for annual event

I like your suggestion, but unfortunately I found a few issues. Here are they are:

If the due month is January, and the person completes the event is December, it is not updating the "due by" column for the next year. With the attachment below, you'll notice Adam completed the event in December. Therefore his new "due by" date should reflect 31 Jan 2015 (not 2014).

Also (and this is an issue I can live with). The completion date should only change the "due by" date if it is within 3 months of the "due by" date. So, Nick having completed the event in February, should not change his "due by" date of 30-JUN-14. But again, this issue is not that important since the event is not scheduled until the person is within the three month window.