A perennial calendar requires the number of weekdays in the year to be evenly divisible by the number of days in the week. This can be achieved by shortening the calendar year to 364 weekdays. Some favor designating one day each year, and another in leap year, as a "blank day."

A blank day is a calendar date removed from the seven-day cycle of the week. These are often proposed as world holidays.

But blank days are objectionable to sabbatarians, or to religious groups who regard every seventh day (sabbath) as a holy day. They feel obligated to include every day in the sabbatical sequence of weekdays, so there are never more than six days between sabbaths.

The Long-Sabbath Calendar Plan achieves a perennial calendar without the use of blank days. It does so by extending some sabbath days (Saturdays and Sundays) for 36 hours.

So Saturday, December 30, 2006, will be followed immediately by Sunday, January 1, 2007. 72 hours are covered by only two weekdays, rather than three, as usual. Consequently, the date of December 31 can be elimated from the calendar, resulting in a calendar year of only 364 days.

The Long-Sabbath plan achieves a perennial calendar without interrupting the continuity of the sabbatical cycle. The calendar year beginning on a Sunday in 2006, will be the same as for 2007, and for every year thereafter.

The next leap year after 2006 will occur in 2008. When January 1 is permanently fixed on a Sunday, the last Saturday in February is the 25th. February's extra day in leap year can therefore be accommodated by extending the sabbaths of February 25th and 26th for 36 hours each. Following this plan, February will always have only 28 days. So the irregular date of February 29th can also be eliminated from the Long-Sabbath Calendar.

The Long Sabbaths at the end of the year will be known as "New-Year Sabbaths." Those near the end of February in leap year will be known as "Leap-Year Sabbaths."

For these 36-hour sabbaths, time can be recorded in two different ways. On the extended clock, time will proceed beyond 23:59 through 35:59. On the 12-hour clock, the long sabbaths will be divided into three 12-hour periods to be designated as follows:

• Saturday, December 30 always consists of:
  1. 12:00 a.m. through 11:59 a.m. (ante meridian)
  2. 12:00 p.m. through 11:59 p.m. (post meridian)
  3. 12:00 a.a. through 11:59 a.a. (ante annum)
• Sunday, January 1 always consists of:
  1. 12:00 p.a. through 11:59 p.a. (post annum)
  2. 12:00 a.m. through 11:59 a.m.
  3. 12:00 p.m. through 11:59 p.m.

• Saturday, February 25 in leap year consists of:
  1. 12:00 a.m. through 11:59 a.m.
  2. 12:00 p.m. through 11:59 p.m.
  3. 12:00 a.q. through 11:59 a.q. (ante quadrennium)
• Sunday, February 26 in leap year consists of:
  1. 12:00 p.q. through 11:59 p.q. (post quadrennium)
  2. 12:00 a.m. through 11:59 a.m.
  3. 12:00 p.m. through 11:59 p.m.

Christmas Day, December 25, will always fall on a Monday. Easter Sunday falls on April 16 in 2006, and so can be fixed on that date perennially.

The year will always contain exactly 52 weeks of seven calendar days, and can be divided evenly into 26-week halves and 13-week quarters.

To distinguish the style of dating introduced in 2006, those dates according to the Long-Sabbath Calendar can be designated by the abbreviation, "L.S." Dates according to the present calendar the Long-Sabbath Plan replaces can be designated by the abbreviation, "N.S." or "New Style," which was once used to distinguish our present calendar's dates from the "Old Style," Julian calendar.