Re: Regular Day-Night - proposed SJ spell

As the most useful place for this spell is to support the in-born circadian 
rythms of the colonists, it need only be used in the living quarters.  (Much 
like how in the Arctic people often cover up the windows and use artificial 
light sources to stay in step with the clocks)  I would say what works here 
is a form of Nchasser's Glowing Globe (Wiz3) - a continual light spell that 
can be set on an infinate timer of brightening and darkening, so that it 
will only provide light during the hours that the colony calls 'daytime', 
and be simply off during 'nighttime'.  For surface towns the reverse spell 
(Concealing Curtain perhaps) would be used as well to create continual 
darknesses during the colonial 'nighttime'.
With these two spells (in 3e they are wonderous items that have the 
prerequisite spells of light, No light or darkness [the item need not follow 
the wording of the spell, just the intent]) used in the building of your 
colonial village the experience would be substantially similar to that of 
people living north of the arctic circle on our standard planet.
AoE:  20 to 30 ft radius each
Cost: the spells both consume the target like continual light does, so about 
1sp per year, plus the item must have an initial value of at least 25gp. 
(3e: the same as the cost of any permanent cantrip item, 1,000gp each)

If you want to grow plants from the homeworld, you'd best do it in window 
boxes around the village, or spend prohibitive amounts to equip entire 
fields with these lightbulbs.