Calendars constitute a most interesting and bewildering part of time measuring. We feel that we have settled the matter by determining the length of the year to within a second of time, and keeping the dates correctly to the nearest day by a leap year every fourth and every fourth century, established by Pope Gregory XIII in 1582, and known as the "Gregorian Calendar." In simple words, our "almanac" is the "Gregorian." We are in the habit of saying glibly that any year divisible by four is a leap year, but this is far from correct. Any year leaving out the _even hundreds_, which is divisible by four is a leap year. _Even hundreds_ are leap when divisible by four. This explains why 1900 was a common year, because _19 hundreds_ is not divisible by four; 2000 will be a leap because _20 hundreds_ is divisible by four; therefore 2100, 2200 and 2300 will be common years and 2400 a leap, etc., to 4000 which must be made common, to keep things straight, in spite of the fact that it is divisible by four both in its hundreds and thousands. But for practical purposes, during more than two thousand years to come, we may simplify the rule to: _Years_ and _even hundreds_ divisible by four are leaps. But great confusion still exists as a result of several countries holding to their own old methods. The present Chinese year has 384 days, 13 months and 13 full moons. Compared with our 1909 it begins on January 21st and will end on February 8, 1910. Last year the China-Japan calendar had 12 months, or moons, but as that is too short they must put in an extra every thirtieth month. We only allow the error to reach one day and correct it with our leap years, but they are not so particular and let the error grow till they require another "moon." The Old Testament is full of moons, and even with all our "modernity" our "feasts" and holy days are often "variable" on account of being mixed up with moons. In Japan the present year is the 42nd of Meiji, that is, the 42nd of the present Emperor's reign. The present is the Jewish 5669. These and others of varying lengths overlap our year in different degrees, so that in trade matters great confusion exists. The Chinese and Japanese publish a trade almanac in parallel columns with ours to avoid this. It is easy to say that we ought to have a uniform calendar all over the world, but the same remark applies just as much to money, weights, measures, and even to language itself. Finally, the difficulty consists in the facts that there are not an even number of days in a year--or in a moon--or moons in a year. "These many moons" is a survival in our daily speech of this old method of measuring by moons. Just a little hint as to the amount of superstition still connected with "new moon" will be enough to make clear the fact that we are not yet quite so "enlightened" as we say we are. While our calendar, or almanac, may be considered as final, we must remember that custom and religion are so mixed up with