[fwdude]

So, “light year” is a misnomer, because year lengths vary?

[mwilli20]

You know before the Internet one might understand this banter... but lately, seriously, you guys have no excuse :-)

Astronomer have defined the year for the purposes of astronomy to be 365.25 days of exactly 86,400 seconds (the SI base unit), totaling exactly 31,557,600 seconds. (According to Wikipedia)

[dirtymac]

so one light year is the distance that a beam of light will travel in one year, +/- the variation on any given year. but still close enough. It will get you in the neighborhood.

But it is still based upon time equaling one earth year.