How do I calculate the date when the sun passes to the top of this building?

Hi, the

I live in Singapore and there is a high-rise building 5km away from my
apartment,
which has a hole in the middle (25X20 meters rectangle). Is it possible to
calculate
the dates when sun rises, I can see the sun inside the hole from my
apartment? (Let's
not consider the likely bad weather for now).

FYI, now, the sun passes a building three blocks away, but no hole in it.

Novice wrote:
Hi, the

I live in Singapore and there is a high-rise building 5km away from my apartment,
which has a hole in the middle (25X20 meters rectangle). Is it possible to calculate
the dates when sun rises, I can see the sun inside the hole from my apartment? (Let's
not consider the likely bad weather for now).


XEphem is an excellent tool
http://www.google.com/search?q=xephem

CALCULATORS: PHYSICS, ASTROPHYSICS & ASTRONOMY
http://www.martindalecenter.com/Calculators3A.html

20 M at 5000 M = 20/5000 radians = 0.004 rad

= approx 0.228 degree

Sun's diameter = 0.5 degree , so it wont fit within the hole.