Nanocentury
October 24th, 2009 at 9:11 amIt’s often useful to quickly estimate run-times of programs and algorithms without using a calculator.
One useful mnemonic to remember is:
seconds is a nanocentury
According to this page the kudos for the quote goes to Tom Duff. However, I found it in many sources online that aren’t even programming related, so I would take this attribution with a grain of salt.
Anyhow, this mnemonic is surprisingly accurate. Disregarding leap years, there are 
seconds in a century (100 years). A nanocentury (
), therefore, contains 3.1536 seconds, which is less than half a percent away from the real value of .
October 30th, 2009 at 16:13
This mnemonic comes from astronomy. It is standard during admissions to grad school to be asked how many seconds there are in a year or century.