September 2, 1909 J 



NA TURE 



277 



STYLES OF THECALEXDAR. 



FEW subjects are more full of pitfalls than that of 

 the change of style and consequent alteration 

 of dates, which therefore requires great care in its 

 consideration. Many articles have appeared from time 

 to time in Notes and Queries, and I would refer to 

 two of my own in 9th S., vol. v., pp. 344, 461. Here 

 I need only say that the dates given in Whitalcer are 

 correct, though it seems to me it would be better to 

 call May 14 .May Day by Julian style instead of old 

 May Dav. It is difficult always to remember that no 

 alteration was made in the difference between the two 

 stvles in 1600, but was in 1700, 1800, and 1900. None 

 will be made in 2000. There was an old saying about 

 St. Barnabas 's Day : — 



" Barnaby, Barnaby, Barnaby bright, 

 The longest day and the shortest night." 



Saints' days, &c., being kept on the same nominal 

 dav, June 11 was still St. Barnabas's Day, though what 

 was that day in the old calendar became June 21 from 

 1582 to 1700, then June 22 from 1701 to 1800, June 23 

 from 1801 to 1900, and now June 24. But the saint's 

 day remaining June 11, the above distich ceased to 

 apply. George III.'s birth was announced as on 

 Mav 24, but when the style was changed in 1752, his 

 hirthdav became June 4, and was kept on that date 

 during his reign. When Gregory XIII. altered the 

 stvle in 1582, the count of days was changed by ten ; 

 when England adopted it in 1752 we had to change 

 the days by eleven; in 1801 this became twelve, and 

 in 1901 thirteen, so that we, differ now from Russia 

 and the Greek Church by that number in our dates. 



The question of an alteration is again being discussed, 

 and uniformity is so desirable that we hope Gregorian 

 usage will be adopted, though it is not ideally perfect, 

 and a better rule would have been to drop a leap- 

 year at the end of each period of 128 years.' The 

 iate Prof. Newcomb thought that the alteration of 

 the style was a mistake, on the ground that there 

 was no particular object in keeping the same dates 

 at the same seasons over very long intervals of time, 

 and the hiatus made by the omission of days caused, 

 as -it was bound to do, great confusion. It is not 

 alwavs recollected that the reason why a change was 

 so long advocated in the western Church, and at last 

 carried out, was the supposed necessity of regulating 

 Easter by the full moon following the vernal equinox, 

 which was supposed to fall on March 21 at the time 

 of the Council of Nicasa, a.d. 325, and really did so 

 in the preceding century. To that epoch, then, every- 

 thing was referred ; otherwise it would have been 

 more natural to have started when the alteration was 

 made bv which the mean calendar year was made 

 nearly of the true length of the tropical year. 



From 1500 to 1700 May Day was kept in England 

 on the day corresponding by the season to what we 

 should now call May 11; after 1700, until the altera- 

 tion of the style in 1752, on what would be May 12 

 by the new reckoning. At that time, then, the dancing 

 round the May-pole, so popular in this country, took 

 place at nearly what is now the middle of the month. 

 It is of interest to remember that the great May-pole 

 in the Strand was removed, in 1717, at the instance 

 of Sir Isaac Newton, to Wanstead, to support the 

 Huyghens telescope of great focal length, which had 

 been lent to Pound (the uncle of Bradley, afterwards 

 Astronomer Royal), who made excellent use of it. 



Christmas Day, of course, and all holy and saints' 

 days, fell, after the /[Iteration of the calendar, several 

 days later, according to the season ; ten days when 

 Gregory XIII. decreed the change in 1582, and eleven 



[ See the writer's "Celestial Motions," eleventh edition, p. 5. 

 NO. 2079, VOL. 81] 



when it was adopted in England in 1752. After igoo 

 the difference between the two styles became thirteen 

 days, and old Christmas Day is marked in Whitaker 

 and other almanacs on January 7. New Year's Day 

 fell seven days afterwards, on the day we now call 

 January 14; that is not marked in Whitaker, but the 

 Russians and the Orientals generally keep it on that 

 day, thirteen days after ours. 



It is, of course, necessary to be very careful in 

 comparing historic events (whether astronomical or 

 otherwise) between 1582 and 1752, English dates being 

 given in old style, and many (not allj of the Continental 

 dates in new style. 



It has been suggested to me that the following 

 tables will be useful for reference in calendar questions. 



The Gregorian calendar was arranged to start from 



the date of the Council of Nicasa in a.d. 



so that 



the vernal equinox should henceforth be made to fall 

 on March 2(, as it was supposed to do then. Table I. 

 gives the dates when the equinoxes and the solstices 

 fell by the Julian style from a.d. 200 to the present 

 century. Table II. gives the dates in Gregorian 

 reckoning of the first dav of Mav and the last day of 

 October (.All Hallows' Eve) for the same centuries. 



It will be noticed that, in the first table, as' the 

 exact times of the equinoxes and solstices vary in 

 different years (according to the distance from leap- 

 year), and also their local times vary in different 

 places, the dates are for the mean, and usually apply 

 to Eurooe. W. T. Lynn. 



