Persian NACO Manual
Dates in the heading
Dates in the heading are ALWAYS Miladi dates. Often they will be converted into alternative years with "or". The citation of these dates depends on how the number is read in words--the words necessary to read the number are represented by the numerals:
1799 or 1800
1800 or 1801 (not 1800 or 1)
1901 or 2, 1902 or 3, etc.
1810 or 11 (not 1810 or 1), 1811 or 12, etc.
1919 or 20
1821 or 2, 1822 or 3, etc.