Arvelie is an alphabetic date format.

The Arvelie calendar has 26 months of 14 days each.

Each month has 2 weeks of 7 days, and each month's name is one of the 26 letters of this alphabet. The 365th day of the year is the Year Day(+00), preceded by the Leap Day(+01) on leap years. The year zero defines when the journaling begins. For example, this wiki was initiated in 2006, which is its year 0. The arvelie date 13A05, is equivalent to January 6th of the 14th year.

The date format is principaly used as part of the daily logs recorded through the Oscean systems, but it was also adopted by others and can be found in the wild.

To calculate the day of the year, convert the month's letter to a value, starting with 0 for A, multiply by 14 and add the day of the month. For example, J05 is equal to (+ 5 (* 9 14)), or 131. Arvelie dates are often accompanied with Neralie time.

Arvelie time can be implemented in a few lines of Uxntal like:

@emit-arv ( doty* year* -- )
	#07d6 SUB2 NIP
	( year ) emit-dec
	( month ) DUP2 #000e DIV2 NIP #11 ADD emit-num
	( digit3 ) #000e [ DIV2k MUL2 SUB2 ] NIP
@emit-dec ( byte -- )
	DUP #0a DIV emit-num
@emit-num ( num -- )
	LIT "0 ADD #18 DEO

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