[time-nuts] WWV, WWVB and Daylight Savings Time

[Mark Sims]

Lady Heather has DST support code in it (in file heathmsc.cpp).   It supports  the current standard settings for several areas (US, Europe, Australia, New Zealand) or you can specify a custom DST rule.  The code is around 200 lines long... some of that is Heather-specific requirements.  It can also be simplified by not parsing the ASCII rule string and using hard coded values.

Implementing and testing seamless DST adjustment is a bit of a pain...  particularly keeping the time correct during the hours before/after the switch.