Hanke-Henry Permanent Calendar

The Hanke-Henry Permanent Calendar, devised by Steve H. Hanke and Richard Conn Henry, is a proposed new calendar which aims to reform the current Gregorian Calendar by making every year identical. With the Hanke-Henry Permanent Calendar, every calendar date always falls on the same day of the week. It is basically the same as the Common-Civil-Calendar-and-Time calendar.

History

In 2004, Richard Conn Henry, a professor of astronomy at Johns Hopkins University, proposed the adoption of a calendar known as Common-Civil-Calendar-and-Time, which he described as a modification to a proposal by Robert McClenon. This version had essentially the same structure given above, but inserted its leap week named "Newton" between June and July. The leap rule was chosen to match the ISO week leap rule, to minimize the variation in the start of the year relative to the Gregorian calendar.

He had advocated transition to the calendar on January 1, 2006 as that is a year in which his calendar and the Gregorian calendar begin the year on the same day. After that date passed, he recommended dropping off December 31, 2006 to start in 2007, or dropping December 30 and 31, 2007 to start 2008.

In late 2011 the calendar was revised by Johns Hopkins economist Steve Hanke by moving the leap week from the middle to the end of the year and renaming it "Extra", producing the Hanke-Henry Permanent Calendar. The target date for universal adoption was January 1, 2017 then, but has been postponed to 2018, when the calendar design was changed in early 2016 to adopt Monday as the start of the week, quarter and year, to better comply with existing international standard ISO 8601.

Year layout

January Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W1 01 02 03 04 05 06 07 W2 08 09 10 11 12 13 14 W3 15 16 17 18 19 20 21 W4 22 23 24 25 26 27 28 W5 29 30 February Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W5 01 02 03 04 05 W6 06 07 08 09 10 11 12 W7 13 14 15 16 17 18 19 W8 20 21 22 23 24 25 26 W9 27 28 29 30 31 32 March Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W9 01 02 03 W10 04 05 06 07 08 09 10 W11 11 12 13 14 15 16 17 W12 18 19 20 21 22 23 24 W13 25 26 27 28 29 30 31 W15 32 33 34 35

April Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W14 01 02 03 04 05 06 07 W15 08 09 10 11 12 13 14 W16 15 16 17 18 19 20 21 W17 22 23 24 25 26 27 28 W18 29 30 May Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W18 01 02 03 04 05 W19 06 07 08 09 10 11 12 W20 13 14 15 16 17 18 19 W21 20 21 22 23 24 25 26 W22 27 28 29 30 31 32 June Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W22 01 02 03 W23 04 05 06 07 08 09 10 W24 11 12 13 14 15 16 17 W25 18 19 20 21 22 23 24 W26 25 26 27 28 29 30 31 W28 32 33 34 35

July Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W27 01 02 03 04 05 06 07 W28 08 09 10 11 12 13 14 W29 15 16 17 18 19 20 21 W30 22 23 24 25 26 27 28 W31 29 30 August Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W31 01 02 03 04 05 W32 06 07 08 09 10 11 12 W33 13 14 15 16 17 18 19 W34 20 21 22 23 24 25 26 W35 27 28 29 30 31 32 September Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W35 01 02 03 W36 04 05 06 07 08 09 10 W37 11 12 13 14 15 16 17 W38 18 19 20 21 22 23 24 W39 25 26 27 28 29 30 31 W41 32 33 34 35

October Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W40 01 02 03 04 05 06 07 W41 08 09 10 11 12 13 14 W42 15 16 17 18 19 20 21 W43 22 23 24 25 26 27 28 W44 29 30 November Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W44 01 02 03 04 05 W45 06 07 08 09 10 11 12 W46 13 14 15 16 17 18 19 W47 20 21 22 23 24 25 26 W48 27 28 29 30 31 32 December Week 1 2 3 4 5 6 7 Sun Mon Tue Wed Thu Fri Sat W48 01 02 03 W49 04 05 06 07 08 09 10 W50 11 12 13 14 15 16 17 W51 18 19 20 21 22 23 24 W52 25 26 27 28 29 30 31 53 32 33 34 35

Correcting for drift

While many calendar reforms aim to make the calendar more accurate, the Hanke-Henry Permanent Calendar focuses on making the calendar perennial, so that every date falls on the same day of the week, year after year. The familiar drift of weekdays with respect to dates results from the fact that the number of days in a physical year (one full orbit of earth around the sun, approximately 365.24 days) is not a multiple of seven. By reducing common years to 364 days (52 weeks), and adding an extra week every five or six years, the Hanke-Henry Permanent Calendar eliminates weekday drift and synchronizes the calendar year with the seasonal change as the Earth circles the Sun. The extra week, or "mini-month", known as "Xtr (or Extra)", would occur every year that either begins or ends in a Thursday on the corresponding Gregorian calendar. The extra week would fall between the end of December and the beginning of January. Leap weeks in 2015, 2020, 2026, 2032, 2037, 2043, 2048, 2054, 2060 …

Under the Hanke-Henry Permanent Calendar there are two 30 day months followed by one month of 31 days. While the Hanke-Henry Permanent Calendar changes the length of the months, the week and days remain the same.

Advantages

• Holidays such as Christmas and New Year's Day as well as birthdays always occur on the same day of the week every year.
• The calendar itself is permanent, it does not change year to year, with the exception of the need to add a week at the end of every 5 or 6 years.
• Quarters all have the same number of days simplifying financial calculations. This calendar would also have prevented Apple’s Q4 2012 reporting fiasco.
• Unlike many other reform proposals, it does not change the days of the week.
• The calendar starts on the same day every year, Sunday, the 1st of January.
• As in the Gregorian calendar, Sunday to Sunday is always seven days, as is Saturday to Saturday, or Friday to Friday. Because no days are ever added outside a seven-day week, there should be no objection from religious groups concerned about weekly holy days. (In proposals that add single days outside the week, a true "seventh day" of rest or worship would drift between weekends and weekdays.)

Disadvantages

• Not as precisely aligned with the solar year as the existing Gregorian calendar and some proposed reform calendars.
• Requires continued use of the Gregorian calendar for certain agricultural purposes.
• All computer date-handling will have to be fixed, which will be much more complicated than the Y2K fix.
• US-biased, not compatible with international standards, such as ISO 8601, which start the week on Monday, hence also the week year. This issue could be resolved by modifying the calendar to begin in a year where 1 January falls on a Monday, instead of a Sunday. e.g. Monday, 1 January 2018 instead of Sunday, 1 January 2012.
• There is no 31st of October, removing Halloween from the current date.

External links

• Hanke-Henry Permanent Calendar Proposal
• "Is it time to overhaul the calendar? Profs have a plan", by Stephanie Pappas, LiveScience Senior Writer, 28 December 2011
• "Proposed calendar would make it same exact day, next year", By Elizabeth Weise, USA Today, 29 December 2011
• "Changing Times" by Steve H. Hanke and Richard Conn Henry, Cato Institute
• "Proposed New Calendar Would Make Time Rational", By Brandon Keim, 28 December 2011
• Press Release: "Time for a Change? Johns Hopkins Scholars Say Calendar Needs Serious Overhaul"
• "Taking Calendar Reform Viral" by Steve H. Hanke, Cato Institute
• "Taking Calendar Reform Viral" by Steve H. Hanke, Huffington Post
• http://www.stratfor.com/image/structure-hanke-henry-permanent-calendar