The earth's orbital direction is such that it lengthens the period for earthbound observers. Why is the synodic period different from the sidereal period? The short answer is because we see the sunlit moon from a slowly moving position: the earth! During the moon cycle, the earth has moved approximately one month along its year-long orbit around the sun, altering our angle of viewpoint, and thus, the phase. Other than that, you get various useful features in these software which include task categories creator, email alert generator, setup calendar appearance.

Also, for students, there is a nice software with features including time table and booklet creator. This figure is called the sidereal period or orbital period. In one of these software, you can also import iCalendar files to add calendar events. If you were to view the moon cycling the earth from outside our solar system (the viewpoint of the stars), the time required is 27.3217 days, roughly two days less. It's the time required for the moon to move to the same position as seen by an observer on earth. The synodic period or lunation is exactly 29.5305882 days. That's true, but it's not exactly one month. You may have personally observed that the moon goes through a complete moon phases cycle in about one month.

Download a detailed Moon Phase Calendar for 2008 - 2015, giving you exact dates and times of all major moon phases.