After yesterday’s discussion of the pope’s role in modifying the leap year rule to keep the calendar astronomically accurate, it may be worth noting an enormous problem that exists in the calendar of another world religion: Islam.
You probably know that in the Muslim calendar the holy month is Ramadan, during which Muslims fast during daylight hours (approximately). But do you know when Ramadan falls during the year?
After recent events in the War on Terror, you might guess that it occurs in the winter on our calendar (remember that there was a question of whether we should use military force in Afghanistan during Ramadan, shortly after 9/11?). That, however, is true only right now. The truth is that Ramadan–like every month in the Islamic calendar–wanders throughout the full range of the year.
The reason is that Muhammad set up a calendar of 354-355 days, almost eleven days shorter than the solar year (which is 365.2422 days). This means that Ramadan is free-floating. Every thirty two and a half years it wanders through the full circuit of the solar year. If a child is born in a year when Ramadan is in the winter then when he is eight years old it will occur in the fall. When he is sixteen it will occur in the summer. When he is twenty-four it will occur in the spring. And when he is thirty-two it will be in winter again.
The same is true not just for Ramadan but for every month and every day of the Muslim calendar. Birthdays, wedding anniversaries, and every other day of the calendar wanders through the course of the solar year. By contrast, geophysical days–equinoxes, solstices, and dates to plant your crops–wander around the calendar.
This virtually destroys the purpose of having a yearly calendar.
The concept of the year is inescapably tied to the motion of the earth around the sun, and to have a calendar that gets the solar year so wrong (by more than three percent!) is useless for periods of more than a handful of years. After that, geophysical considerations make it obsolete, and people have to fall back on something other than the calendar to figure out when to plant their crops and so forth.
(Another problem–which I won’t really go into–is that Muslim countries are not even all agreed on when precisely different months begin. Ramadan, or any other month, may begin on one day in one nation but on nearby day in a different nation. It depends on what the clerics say.)
As a result, the Muslim timekeeping system is not suited to the modern age or to a global economy. It is destined to become a liturgical calendar that is detached from the realities of global life. Since the business world today uses the Gregorian calendar set up by Pope Gregory XIII, Muslims will increasingly use that calendar to the extent that their nations develop. This will only inflame the passions of Muslim radicals who want everyone in the world to use the calendar their faith employs. Seeing the West further exalted as Muslim countries increasingly use the Western calendar–seeing that being successful today means being Western–will not be good for future relations.
The ultimate reason for this is not that when the Muslim calendar was set up that people knew less about the solar year. At that time in the west the Julian calendar, which is far more accurate, was already in use. When in the 1500s the Julian calendar got ten days out of synch with the solar year (less than the Muslim calendar slips out of synch with it each year), Westerners considered it intolerable and fixed the calendar so that it would stay accurate for millennia. People have known the length of the solar year to within a day for thousands of years. The reason the Islamic calendar is so problematic, simply put, is that Muhammad was no astronomer.
I guess if I want to see giant snails menacing people, I’ll have to go rent 
Can you see this man wearing Spock ears at a Trek convention?
