I just gotta ask... How is it that people in 1582 could figure out that an earth year was 365.2422 days long? How did they measure it with that precision? By using 1/10000 day precision, we're talking 8.64 seconds per _year_. They eliminated 10 days off the calendar in October 1582. Based on what measurement? BTW, IBM date data type accepts 10/10/1582 as a valid date. Maybe we should ask them to fix that??? <g> So many questions... - Dan Bale ________________________ Original Messages ___________________________ From: email@example.com (Douglas Handy) Subject: Re: [Feb 29, 2000] >The Gregorian calendar had just been introduced that century(!?!? or was >it the one before?) According to Paul Conte's infamous date routines, the dates skipped were Oct 5, 1582 thru Oct 14, 1582. It could be noted that his routines ("The Last Date Routines You'll Ever Need") return these as invalid dates. ------------------------------ Date: Thu, 30 Sep 1999 10:23 +0700 From: "Harry D. Angkasa" <firstname.lastname@example.org> Subject: Re: Feb 29, 2000 The Sun goes around the globe are 365.2422 days. To make it easier Gregorius made 365 for a year. For February, he made 28 days for February, and 29 days for every 4 years to make correction. The average days for 4 years would be (365+365+365+366)/4 = 365.25 days per year. It is not so accurate, isn't it? . That is why he made another rule : - 365 days for every 100 years, even though it can be divide by 4. - 366 days for every 400 years. That rule will make a correction of minus 3 days for every 400 years, or -3/400 = -0.0075. With this correction, 1 year become 365.25 - 0.0075 = 365.2425 He ignored the different value of 0.0003 days. ------------------------------ From The Origin of Leap Year Pope Gregory XIII took action in the year 1582 by cutting 10 days off the month of October and devising the Gregorian Calendar, the one we still use today. The last day of the Julian Calendar was Thursday, October 4th, 1582, followed by Friday, October 15th, 1582. Clavius' solution was to make no Centennial Year a leap year unless it was divisible by 400. Since 1600 was coming up, it was noted that it would be a leap year, whereas 1700, 1800 and 1900 would not. The year 2000 will be a Centennial Leap Year. He also realized that this solution slightly overcorrected the calendar. Therefore, any year that is divisible by 4,000 would be called a Common Year and would not be a leap year. This has the effect of bringing the calendar back in line. There will not be a Common Centennial Year until the year 4000. +--- | This is the Midrange System Mailing List! | To submit a new message, send your mail to MIDRANGE-L@midrange.com. | To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com. | To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com. | Questions should be directed to the list owner/operator: email@example.com +---
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