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I'm guessing that he's saying binary doesn't represent all numbers properly so if you need it to be absolutely accurate, you need to have a custom data type. Making it picoseconds doesn't help.

Same problem with money - it's a very bad idea to use floats etc for money.

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I covered that. There is no "absolutely accurate" in a finite number of bits, no matter what data type you use. In N bits, you can't store more than 2^N distinct numbers, and there happen to be a lot more than 2^N distinct numbers, even between 0 and 1. You have to choose your margin for error and be prepared to live with it (or use a variable width format).

Fully agree. The time resolution I would be interested in are nanoseconds. Using 64bit signed integer values with nanoseconds as units I could cover a +/- 292 years which is far enough. I could then afford to keep the unix time_t epoch.

You did cover it, you're right :)

Is a solution for money to convert everything to cents?

That can work, for some tasks. Lookit this article for more info: http://www2.hursley.ibm.com/decimal/decifaq1.html#inexact

Many languages have built-in formats for decimal data, so unless you have a really good reason (space/speed), just use those.

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