The Moon In January . ... Explanation: Reckoning dates by Universal Time, the next full moon will be on Sunday, January 31. Since the last was on January 2nd, Sunday's full moon will be the second this month. ... Well, the moon's phases repeat every 29.5 days and most months have 30 or 31 days, so a Blue Moon is certainly possible if not a common event. In fact, the next (and last) Blue Moon in 1999 will occur in March, leaving February without a full moon at all. ...