[[File:HHCalendar.png|Hanke-Henry Permanent Calendar Proposal|thumb]]While many [[calendar reform]]s aim to make the calendar more accurate, the Hanke-Henry Permanent Calendar focuses on making the calendar [[Perennial calendar|perennial]], so that every date falls on the same day of the week, year after year.<ref name=jhu.edu/> 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)",<ref name=jhu.edu/> occurs every year that either begins or ends in a Thursday on the corresponding Gregorian calendar,<ref name=jhu.edu/> and falls between the end of December and the beginning of January. Thus, each year always begins between December 28 and January 3 in the Gregorian calendar.there would be no holloween