JANUARY TO DECEMBER.

Auckland Star, Volume LXIV, Issue 1, 3 January 1933, Page 6

JANUARY TO DECEMBER.

HOW MONTHS WERE NAMED. (By F.R.A.S.) The month is defined astronomically as that interval of time which lies between one new moon and the next, or a "nioonth." Its mean length is 29.53059 days. Owing, however, to the fact that the orbits of the earth and the moon are-not exact circles, the month varies to the extent of 13 hours. The mean is known technically as the "synodic month," while the "sidereal month" (or period of the moon's revolution about its primary, indicated by the stars in the lunar •background as viewed from the earth) is on the average 27.321GG days in length. A year is made up of" 12.309 synodic or 13.309 sidereal months. Then there is the "anomalistic month," the period of time of the moon's revolution between two successive nearest approaches to the earth, or from perigee to perigee, as the astronomer terms it This is 27.55400 days in length. Then there is' further the "nodical month" of 27.21222 days, the interval between the moon's passage from and return to the same node. It will be seen that many complications must bo allowed for. Some arrangement, therefore, has to be accepted as representing the length of the month for practical uses, in order to rectify the confusion that existed prior to Lis turn-, Julius Caesar enacted that the alternative months, January, March, May, July, September and November, should each have 31 days, while April, June, August, October and December should 'each have 30. The only exception, February, was to take 29 days ordinarily, and 30 every fourth year thus adjusting the civil with the astronomical year. The cause of the subsequent relapse into confusion does not make pleasant reading, though it may bo interesting. It is at least bad enough to bo interesting. Frankly stated, the simple order adopted by the great Roman Emperor was broken up out of slieer vanity and vexation of spirit. The fourth month, August, had been named after Augustus. It was thought out ot keeping, however, with the order of things that July, named after Julius Caesar, should have a day more than August, even though it was Caesar who reformed the calendar. A day, therefore, was filched from February and added to Auguat in order to make up its unthinkable (!) deficiency. To avoid the coming together of three months of 31 days each, September and November were reduced to 30 days, and October and December lengthened out so as to have 31 eacii. This capricious frivolity has involved us in a mess that has never been cleared up. Why, too, should we still be speaking of the last four months ot the year as September (from septem, Latin for seven), October (octo, eight), November (novem, nine) and December (decern, ten), when they are really the ninth, tenth, eleventh and twelfth respectively? The answer is simple: It is an absurd reminiscence of the ancient Roman days when the year began with March, the seventh month rightlv being called September, and so on The oft-discussed reformation of the calendar will doubtless take effect some day. The months will then, it is to be hoped, be baptised with more appropriate names. The difficulties in- the way of a satisfactory division of time are twofold. A calendar could be produced which will be convenient and perfectly the same from year to year if. for one thing, it were not for the fact that the year contains about 52 weeks, from which it follows that there must be 13 months of four weeks each if they are all to be of uniform length. The second difficulty is that the ordinary year contains one more day (the leap yeer two" days) than 52 weeks. From this it follows that one day (or two days) must be omitted from the counting of weeks if all years are to begin on the same day of the week. A year of 12 months is easily divisible into halves, thirds and quarters, and is therefore more desirable than one of 13 months. Yet the advantages of-having all months of the same length make the calendar of 13 months the more preferable. A proposal has been made to dispense with the extra day beyond 52 weeks of the ordinary year by having a New Year's Day which belongs to no week or month. In this scheme a corresponding special holiday would be inserted into the middle of the year. In America business and commercial organisations in increasing numbers are using a year of 13 months for their accounting, and there is a steadily-growing sentiment in favour of a thorough reform in the matter of the calendar.