[Datetime-SIG] Calendar vs timespan calculations...

[Alexander Belopolsky]

On Sat, Aug 1, 2015 at 10:36 AM, Alexander Belopolsky
<alexander.belopolsky at gmail.com> wrote:
> So how do you represent  three outcomes [], [u] or [u0, u1] in a way that xG(t)
> always works?  My solution:
>
> [] -> [u1, u0]
> [u] -> [u, u]
> [u0, u1] -> [u0, u1]

Let me clarify what I propose to return for the local time in a gap:
the two values u1 and u0 are *not* solutions to L(u) = t.   For t in a
gap, no such solutions exist.  Instead, u0 is the solution for L0(u) =
t where L0 is L linearly extrapolated from the times before the gap
forward and u1 is the solution for L1(u) = t where L1 is L linearly
extrapolated from the times after the gap back.

In the case of the US-style spring jump from 01:59 to 03:00 AM, for t
= 02:30 AM, u0 is such that L(u0) = 03:30 AM (this is the "what a
meant when I said 02:30" time) and L(u1) = 01:30 AM.