In what sense Unix clock is UTC? Unix clock is to a first approximation defined as number of second that have passed since a particular fixed point in time. As

In what sense Unix clock is UTC? Unix clock is to a first approximation defined as number of second that have passed since a particular fixed point in time. As such, timezone considerations are pretty much immaterial to what Unix clock is. This definition of Unix clock is only mostly correct, due to its treatment of leap seconds, but the way they are treated in Unix clock is not like how they are treated in UTC anyway (some Unix seconds last 2 SI seconds), so in this sense, Unix clock is not UTC either.