The backup capacitor was upgraded from 4.7 mF to 1 F, now capable of a year's worth of timekeeping;
Approximate sunrise/sunset time calculations. In the previous version, the PIC only knew the sunrise/sunset for dates between Oct 1 and Feb 28 (the program memory on this thing is extremely scarce!). Now the daylight data is sparsely stored, at one entry per 16 days. The sunrise/sunset points for the days in between are interpolated. Now it sports a full-year daylight calculations.
The sun simulation is shifted somewhat ahead in the future — by 35 days, to be exact. As now we're approaching the autumn equinox, the lamp would illuminate as if it were about the end of October. The idea is to make the poinsettia blossom earlier - instead of the "natural" December-January, I'm aiming for November-December.
Whether the plant would get red by Christmas - keeping my fingers crossed - it's about to be tested :)
