At least to anyone who tends to calculate these things the "western" way. Jews, Muslims, Chinese, Indians and anyone from those cultures which employ any one of the estimated 40+ calendars in use today other than the standard western calendar can simply put the best wishes on hold and apply them whenever they feel appropriate.
But why 2058? Well, one could just as easily ask "why 2013?". That number was arrived at by the sixth century scholar Dionysus Exiguus who was trying to calculate a table predicting the dates of Easter, a moveable feast of some importance to himself being a christian. Any sane man would have simply walked across the street and knocked on the door of one's nearest Jewish neighbour to ask him. After all they had centuries of experience calculating Passover based on a lunasolar calendar and in particular the occurrence of the first full moon after the vernal equinox, a calculation based on astronomical observation originally from ancient Babylon but which Jews had converted into pure mathematics. Dionysus decided to go it alone however and found that he had basically nothing to go on except a period of 19 years during Diocletian's reign when a serious effort had been made to get the equinox to match with March 21st every year and the calculations used had been preserved. He borrowed these calculations and then simply extended this cycle forwards and backwards beyond the "anno Diocletian" years and ended up with "anno Domini" years instead (though A.Dio 248 thus became A.Dom 532) and the count was started from whichever 19 year cycle in retrospect had begun in an around the birth of Jesus Christ, whose alleged resurrection was the whole point of the exercise for Dionysus.
However it is the date of March 21st which should raise an eyebrow amongst discerning calendarites. Why were Dionysus and the christian church intent on getting a moveable feast linked to a specific date in the year? Of course the answer to this is that like every other Roman citizen for almost six centuries they were subscribers to a particular calendar system which had been initiated by a Pontifex Maximus all those years previously, a certain young political wannabe called Julius Caesar who would later go on to affect history through more martial means, though it is arguable that it was his calendar reform which was to provide this ambitious man with his longest lasting historical legacy. That there was even a day which could be called March 21st and which popped up regularly in springtime was thanks in no small measure to JC.
This March 21st obsession within the church didn't dissipate as the years went on. In the 16th century Pope Gregory famously had to make another huge adjustment to the Julian calendar (or the Sosigeneal calendar, as it might be most accurately named - JC simply enacted the recommendations of the Alexandrine astronomer Sosigenes). Gregory's motivation, just as with Dionysus, was to get Easter back on track with the vernal equinox. When Gregory snipped ten days from October in 1582 (a period in which no important saints would be miffed by losing that year's day dedicated to them) he ensured that the vernal equinox of 1583 would be on the desired date. Moreover his readjustment in the calculation of leap years helped ensure that this time it would stay on track a good while longer.
And there is one other thing that must therefore now be quite obvious about March 21st. The christian obsession with getting the vernal equinox to coincide with that fixed date reflected their inheritance of a solar calendar by which a year was defined (Roman) and a lunasolar calendar (Jewish) by which Easter was defined. The ecclesiastical year therefore required a starting date from which all moveable feasts that year could then be dated and it would be better for everyone if it was a fixed date every year. March 21st was therefore New Year's Day, at least in the ecclesiastical mind.
That the year should have an official start date suited a lot of people besides the church too. In the world of commerce a fixed calendar was also becoming more and more important, and one which was generally adhered to by everyone in Europe held huge appeal in that quarter. The church's inference that their revamped Julian calendar began on a preferred date was fine by merchants too.
Or at least it was until the flaw in Gregory's calendar became obvious. His adjustment after all had been to anchor a moveable feast dictated by lunar cycles to a nomenclature of date names which belonged to a solar cycle. Easter - as it still does - therefore happily moves about within a four to five week period depending on the year. March 21st could be the start of Lent one year, bang in the middle of it the next, and even the start of Easter itself on other occasions. From a commercial point of view therefore it was worse than meaningless, arbitrarily arriving inside and outside of a period in which commercial activity may or may not be feasible, a most unsuitable time of year as a starting point. Others were complaining too. Record keepers, book keepers, annalists and just about anyone who liked to put a number on the year had long ago decided that the church's failure to declare the start of the ecclesiastical year as its official start meant that the system needed yet another reappraisal. Some were opting for March 1st, some April 1st (tax authorities in many countries still adhere to that one), some for December 25th and some desperate christians even went right back to the Jewish calendar and took September 1st as the date nearest Rosh Hashana, which at least was a New Year's Day that Jesus might remember.
However one trend prevailed, and again we have Julius Caesar to thank for it. Faced with a similar dilemma regarding what date started any year JC had declared the Nones of Janus (1st January) as the day that everyone stick to. After his assassination there was a bit of a lapse but under Augustus the decision became law and this date had therefore been a well established start of the solar calendar year when that calendar formed the basis of the church's own. The church however considered it rather a pagan notion and largely ignored it for over a millennium, but throughout this time it had always retained a small group of adherents who had kept its significance as New Year's Day, whether or not they actually counted the years according to Dionysus's table, or were even christians at all. In the 18th century, when increasing calls for standardisation reflected the age's enlightenment and nascent industrialisation, it was to JC's system therefore that all heads again turned.
So what have we now? A solar calendar which is one part Gregory (the improved leap year bit), one part Dionysus (the number bit) and all other parts Julian. If one looks at it this way one can readily see that the bit of least importance is Dionysus's - after all most people are sceptical that he managed to count accurately from Jesus's birth anyway. So, let's just drop the faulty bit and give the numbering over to JC, along with almost everything else about our year.
Which of course brings us right back to the year dot, the final year before our calendar kicked in and known to those who lived in it as "the year of confusion" in which Julius Caesar imposed an extra 90 days in order to bring everything back in sync from there on. Dionysus would have us believe it was 45BC, but we know that's a load of cobblers. Just like 2013 is therefore.
If we are to be totally faithful to the calendar to which we subscribe and call today New Year's Day, then let's also give it back those 45 years excised through clerical error. Here's to Julius for enforcing it, here's to Gregory for fixing it, and here's to 2058!Pope Gregory XIII