[Datetime-SIG] DST explained visually

Tim Peters tim.peters at gmail.com
Wed Aug 26 22:12:11 CEST 2015

> I have edited [1] your sketch to show the UTC mappings of two local times: g
> in the gap and f in the fold: (g, fold=0) maps to G0, (g, fold=1) maps to
> G1, (f, fold=0) maps to F0, and (f, fold=1) maps to F1. Note that G1 < G0
> while F1 > F0.  This may look arbitrary, but it follows from a consistent
> rule: fold=0 is the intersection with the line that is solid (valid) before
> the transition and fold=1 is the intersection with the line that is solid
> (valid) after the transition.
> [1]: https://github.com/abalkin/ltdf/blob/master/dst-visual.jpg

So we're switching to a boolean flag again, named solidbefore?  The
great advantage to that would be easy of finding via Google.  While
there a hundred times more hits on "python which" than on "python
fold", there are still over 800,000 hits on the latter.  There only 7

    python "solidbefore"

although you need the quotes to cut it back from some thousands ;-)

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