Talk:360-day calendar

Why?
Someone wrote a comment in the article asking why the US used it's particular 360 day calendar variant, and what the advantages of it were. I removed it because it was unencyclopedic, but the answer would be a good thing to put in the article, if anyone knows.--82.45.163.18 17:25, 9 October 2006 (UTC)


 * The reality is that local practices evolve and then standardisation usually follows when the advantages of normalisation across trading units mean that the benefits of standardisation outweigh the change costs and politics of convergence. Actuarial practice is no different in this than many other regimes.  Why does the US cling to non-metric units? ...  This is good topic to bring up in discussion but I am not sure if it adds value to the main article.  TerryE (talk) 16:45, 6 August 2008 (UTC)

Leap Years
How is 29 February handled in each of the systems?
 * From the article: "12 months of 30 days each" +mwtoews 20:24, 13 May 2007 (UTC)

Quoted Formulae Are Wrong
The formulae given are simply incorrect. The correct ones are as follows:
 * 30E/360
 * If either the first date or last date of the accrual period falls on the 31st of a month, that date will be changed to the 30th.
 * If the last day of the accrual period falls on the last day of February, the month of February will not be extended to a 30-day month and the actual number of days in February will be used.
 * 30US/360
 * If the last date of the accrual period is the last day of February and the first date of the period is the last day of February, then the last date of the period will be changed to the 30th.
 * If the first date of the accrual period falls on the 31st of a month or is the last day of February, that date will be changed to the 30th of the month.
 * If the first date of the accrual period falls on the 30th of a month after applying (2) above, and the last date of the period falls on the 31st of a month, the last date will be changed to the 30th of the month.

Out of courtesy to other posters, I will leave it for a few days to get any feedback before rewording the text.

I can also give a citation for the Excel bug. TerryE (talk) 04:06, 2 January 2008 (UTC)
 * Just made these changes. Sorry but I forgot to log in so they are stamped with my IP address TerryE (talk) 00:01, 10 January 2008 (UTC)

Certain days are skipped
"To derive such a calendar from the standard Gregorian calendar, certain days are skipped." Aren't a couple of days added too (to February)? J IM ptalk·cont 06:18, 22 January 2013 (UTC)

Another method
Many years ago, I saw a printed calendar which showed a "bank day" number for each day of the year, als well as the number of bank days remaining till the end of the year (361-x). Out of curiosity, I checked how it differed from normal day numbering. After each streak of 60 days, there was one day where the number didn't advance. So, in a standard year, you would have (in total) five non-bank-days between days 60 and 61, 120 and 121, etc'. In a leap year, 31-Dec would be a non-bank-day as well. Using this system might or might not yield results identical to one of the methods listed in the article, but it's much easier to handle algorithmically.