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A recent thread which discussed the various formats available in the WP-34s for representing dates and times got me thinking.

I don't like to see a calculator having so many arbitrary date/time input/output format options catering to different cultural traditions, when there is one sensible standard human-readable but culture-free (apart from using the Gregorian calendar) format promoted by international standards for technical work.

That format is YYYY-MM-DD HH:MM:SS . See http://www.iso.org/iso/iso8601. For calculators the equivalent would be YYYYMMDD.HHMMSS, with the seconds truncated if they can't fit. Human-readable time quantities can be represented on a calculator in a compatible format: D.HHMMSSs . I realise that would be incompatible with the degree-min-sec format and its conversion functions, but we are dealing with different units.

We need to get used to one sensible standard format for technical work, and stop cluttering up our devices with so many options that just get in the way. I admire the spirit behind the 34s, and might be interested in getting one myself, but just wish it wasn't so cluttered. I'm eagerly watching the progress of the 43s; maybe the developers might consider these points.


P.S. 35s users (and others) might be interested in revisiting a set of date/time programs I posted a while back: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv021.cgi?read=252087

You're completely right :-) but real life is different ;-)

Please see the respective remarks in the WP 34S Owner's Manual in the chapter about "localisation".




We need to get used to one sensible standard format for technical work...

... like the metric system (ISO 31). Would save a lot of conversion factors if everybody could adapt to that :-)

...catering to different cultural traditions...

... which I would not want to give up just to save a couple of bytes for a pocket calculator operating system!


You are talking about time stamps which always combine a date with a time. These should be considered time zone independent. So the internal form of a time stamp needs to be something like YYYYMMDDhhmmss.frac UTC or even a value seconds.frac based on a certain point in time. The former is used by SAP while the latter is more often seen in Unix like environments.

A time value is a different beast because it denotes either a recurring point in (local) time or a duration, not a fixed point in time.

A date value is not a single point in time either, but a time interval of 24 hours and should always be considered local.

The latter two are local and should be displayed as such.