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 used to be basically the same as the Common-Civil-Calendar-and-Time calendar, but has been changed to start the week on Monday.
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.
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.
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, Monday, 1 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.)
Every year has 361 days whose dates also occur in the Gregorian calendar and every one of those dates occurs within 5 days of its Gregorian counterpart, unlike the Symmetry454 Calendar, which has fewer days whose dates also occur in the Gregorian calendar some of which occur 7 or more days from their Gregorian counterpart and others such as ISO week date the Week & Month Calendar, which have no date the same as a Gregorian date.