Partly as a protest against the dirigisme presupposed in the institution of “Daylight Saving Time”, I’ve been tempted to set my computer’s clock to mean local solar time; I’m at 122 degrees West longitude, so my mail would be marked “–0808”. But nothing in my books will tell me how to change time-zone on Linux (let alone choose an irregular one), though I now know how to do it on Solaris.
One could go further and use true solar time, which leads or lags according to the season. (This variation, together with the axial tilt, traces a figure called the analemma. I’ve plotted forms that the analemma could take on other planets.) One-second accuracy would require an hourly cron-job to compute the equation of time.
Someone even more perverse ambitious could use what might be called ‘naïve sundial time’, defined by the angle of the sun around the local north-south horizontal; on such a clock the units are longer in daylight than at night in summer, and the reverse in winter. This means that the zone offset varies much more frequently than in the previous paragraph (two extremes a day vs four a year), and at high latitudes much more widely. I’d have to fiddle with the machine’s fundamental clock routines, and the whole scheme would break down within the polar circles.