What is the meaning of Eternal September?

Eternal September, is also known as the September that never ended:

All time since September 1993. One of the seasonal rhythms of the Usenet used to be the annual September influx of clueless newbies who, lacking any sense of netiquette, made a general nuisance of themselves. This coincided with people starting college, getting their first internet accounts, and plunging in without bothering to learn what was acceptable. These relatively small drafts of newbies could be assimilated within a few months. But in September 1993, AOL users became able to post to Usenet, nearly overwhelming the old-timers' capacity to acculturate them; to those who nostalgically recall the period before, this triggered an inexorable decline in the quality of discussions on newsgroups. Syn. eternal September.

definition from: the jargon file

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