The moon. It has been a recurring topic of discussion among Torah Observant groups in recent years. Not so much because of its size or shape or composition, but due to its use in ascertaining the Biblical months. That is, which lunar phases should be use to start counting the days of a month? Some argue for a crescent moon (the first visible sliver of a waxing phase); others for a conjunction (an astronomical moment in time when the moon is not visible at all). Yet still others have argued – albeit rarely – for a full moon. Then there are those who reject this lunar observation entirely in favor of a strictly solar calendar. By that I mean, that the moon is not used for determining or setting the months at all, and instead it should be the sun. This would mean a month (in Biblical terminology) would be a set number of days (either 30 or 31, depending on which variation of solar calendar theory one opts for), rather than the 29/30 days alternating found in the lunar calendar.