Challenge: Nerd Reference of the Arbitrary (Multi-rate) Time Period

What is this a reference to:
lO"$

Anyone who knows what it is without Googling it gets the coveted Sarcastic Weasel Big-Ol' Nerd Award.

A successful Google search answer deserves a Sarcastic Weasel Minor Nerd Prop (given the fact that the search term has a quotation mark in it).

A person successfully describing the above reference and guessing how it came to my attention (and who has an email address that I know) will win an actual, honest to God prize (not like all of the metaphorical prizes I've (not) given out in the past.

Disclaimer: The Sarcastic Weasel's judgments are arbitrary and life is unfair.