Felly sgrifennodd Robbie :
I believe the link was in a thread connected with why nights continued
to get lighter after the longest day and darker after the shortest day

Sorry I don't have the site, but I think you're only partially right here.
Evenings continue to get lighter after 21st June for a few days. Mornings
reach their peak before 21st June.

Conversely in the winter, evenings turn the corner around 13th December,
but mornings not until around the new year (which is the other way around
to what you'd remembered).

Adrian

--
Adrian Shaw ais@
Adran Cyfrifiadureg, Prifysgol Cymru, aber.
Aberystwyth, Ceredigion, Cymru ac.
http://users.aber.ac.uk/ais uk