Jim Bacon wrote: >next_dst and prev_dst based on the year value of the DT object and a >parameter specifying if what is wanted is the spring or fall date, or at >least specifying change to daylight time or standard time.
Please no, not such a restrictive model. That'd be a nightmare. Timezone offset changes are a lot more complicated than just a twice-yearly alternation between two possibilities. There are years with more than two changes, and years with only one change or no change at all. With the generic arrangement, where you get the next/previous observance boundary working from an arbitrary DT, if you happen to know that your timezone fits the twice-yearly-change pattern, you can do next from the start of the year or previous from the end of the year to find the two boundaries. -zefram
