I don't think either one is a large problem, Pierre. The context will
clearly show what is meant. And the universe is only some 14 gigayears
old (give or take) anyway according to current cosmology.
Off the top of my head (!) I think ISO/IEC 80000 series stipulates a; it
may allow y as an alternative. IEEE/ASTM SI-10, "American Standard for
Use of the International System of Units (SI): The Modern Metric System"
uses y. NIST SP 811 does not show a symbol in its conversion table.
As you know, the year is not a unit accepted for use with the SI, there
being several different definitions for "year".
Jim
Pierre Abbat wrote:
I've seen "y", "a", and "ya" as symbols for year ("ya" actually for "years
ago"). Both "y" and "a" have problems:
*If "a" means year, then a petayear is "Pa", but that's a pascal.
*If "y" means year, then a gigayear is "Gy", but that's a gray.
Anyone have a better suggestion for a symbol for year?
Pierre
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