enaeher/local-time-duration — pull request #5 by leetayres (2014-11-04 13:58:26+00:00)
Title: Adjust timestamp-difference to address DST boundary

With the current implementation of local-time the timestamp-duration+ and timestamp-duration- operations will adjust the result when it crosses a DST boundary. However timestamp-difference does not. This results in the following, which feels inconsistent to me.

(setf test-diff (start end)
(ltd::timestamp-duration+

(let ((start @2014-11-02T00:00:00.000000-05:00)
(end @2014-11-03T00:00:00.000000-06:00))
(ltd::timestamp-duration+
start (ltd::timestamp-difference end start)))

=> @2014-11-03T01:00:00.000000-06:00