what is the arvelie date system?
introduction
The Arvelie calendar is a compact alternative date system developed by Devine Lu Linvega. It is designed to emphasize regularity, computational simplicity, and personal contextualization of time.
Arvelie dates are written in the format YYMDD. The year count begins at zero relative to an arbitrary but meaningful reference point, most commonly the start of a project or journal. The calendar consists of 26 months, each represented by a letter of the Latin alphabet (A–Z). Every month contains exactly two weeks of seven days, resulting in a uniform structure of 14 days per month.
Using 2025 as the base year, the following examples illustrate the system:
- January 1, 2025 ->
00A00 - April 1, 2025 ->
00G06 - October 5, 2025 ->
00T11 - December 31, 2025 ->
00+00 - March 15, 2027 ->
02F03
conceptual motivation
A defining characteristic of the Arvelie system is its rejection of an absolute historical epoch in favor of a relative temporal framework. Conventional calendars typically anchor time to distant historical or religious events, such as AD (Anno Domini) or BC (Before Christ). By contrast, Arvelie permits the user to define year zero according to personal significance—for example, the inception of a website or creative project.
This relativity aligns closely with everyday human conceptions of time. Age is measured from birth, professional experience from a start date, and relationships through the use of anniversaries. Arvelie formalizes this intuitive practice, shifting emphasis from an abstract global timeline to the duration and development of a specific endeavor. For this reason, it is particularly well suited to a personal site such as the one you are currently reading.
Structurally, the calendar is notable for its uniformity: 26 identical fortnights per year. This eliminates irregular month lengths and exception-heavy rules, improves lexical date sorting, and yields concise, visually distinctive date strings that remain legible.
intercalary days
The Arvelie calendar accounts for surplus solar days through the use of intercalary days. After the final month (Z), a special Year Day is inserted, denoted as +00. This day exists outside the standard month–week structure and represents the final day of the year, e.g., 2025-12-31 is translated to 00+00.
In leap years, an additional Leap Day follows the Year Day and is written as +01. Like the Year Day, it does not belong to any month. For example, in 2028, 2028-12-30 corresponds to 03+00 (Year Day), and 2028-12-31 corresponds to 03+01 (Leap Day).
implementation on this site
This site launched in 2025, which is therefore designated as year 00. All dates published during 2025 begin with 00, incrementing to 01 in 2026, and so forth. This approach explicitly ties the calendar to the lifespan of the project itself.
Technically, the system is implemented using a Hugo partial (date-arvelie.html) that converts standard post dates within my HTML templates, as well as a shortcode (arvelie.html) for direct use in Markdown. The examples above were generated using this shortcode. The underlying logic draws significant inspiration from the Arvelie CLI implementation by Tillman Jex.
final thoughts
While the Arvelie date system represents only a modest departure from conventional calendrical practice, its impact on the tone and coherence of this site is substantial. By allowing timekeeping to evolve alongside the project it documents, Arvelie transforms dates from static timestamps into indicators of growth and duration. As the year count advances from zero, the calendar will not merely record when content was created, but how far this project has progressed over time.
further reading
- Linvega, Devine Lu. Arvelie Calendar. https://wiki.xxiivv.com/site/arvelie.html
- Jex, Tillman. The Arvelie Time System. https://tjex.net/posts/the-arveelie-time-system/
- Richards, E. G. Mapping Time: The Calendar and Its History. Oxford University Press.
- Zerubavel, Eviatar. The Seven Day Circle: The History and Meaning of the Week. University of Chicago Press.