Thank for the ideas.  The 'date' command examples look interesting.

I think R would not be too unwieldy as a hammer here.  My use case  is a
humble one: just take a several clock times in HH:MM format (utc) and
adjust to  another timezone by adding or subtracting the relevant number of
hours.  The day of week is not important; i will have to deal with it.  I
did imagine a conditional subtraction by adding of subtracting 24:00 as
needed.

Much thanks for the advice.

Alan




On Sat, Dec 12, 2020, 15:00 Tim Cross <theophilusx@gmail.com> wrote:

>
> Maxim Nikulin <manikulin@gmail.com> writes:
>
> > 2020-12-12 Alan E. Davis wrote:
> >>
> >> Thank for the clear explanation.  My little problem seems to require a
> >> super steam hammer.  Your insights are most helpful.
> >
> > In my opinion, org mode is too rigid in respect to timestamp format.
> > Sometimes I would prefer to specify timestamps with timezone.
> >
> > Well known example of idiosyncrasy of particular applications.
> > Timestamps in xls files are represented by floating point numbers,
> > namely days since 1 Jan 1900, fractional part is time. Unfortunately
> > 1900 is not a leap year, so to avoid unnecessary complications of code
> > and keep memory footprint small, on Macs epoch starts in 1904, on
> > windows year 1900 has Feb, 29...
>
> Although there are likely some dark corners where bugs can be found, I
> think you could probably add timezone data to org timestamps by changing
> the default format strings. Org also uses an 'internal' 'time' value to
> represent timestamps which are then converted to the required format
> using these format strings.
>
> What is possibly missing is an easy way to specify a time zone when
> creating a timestamp. I suspect it will default to whatever the local
> system tz is and I don't think there is any convenient way to change tz
> values like there is for the other timestamp components.
>
> --
> Tim Cross
>
>