Calculate sunrise / sunset

[abhijit]

I'd like to set up functions to calculate sunrise and sunset times. I don't need huge precision; just a rough estimate (like within a half hour) would do. But then again, I certainly wouldn't complain about a solution with high precision.

Ideally you'd just send the function latitude and longitude coordinates. Something like:

Public Function Sunrise(pdblLatitude As Double, pdblLongitude As Double) As Date
End Function

Public Function Sunset(pdblLatitude As Double, pdblLongitude As Double) As Date
End Function

Google turned up a ton of possible ways to go, none of which made a lick of sense to me.

Have you considered using a webservice to achieve this goal?

I would write a .NET component to call a webservice. Then build a COM wrapper around the .NET component and call the functions exposed by the COM wrapper.

I have done something similar when my VB6 app needed to call a webservice running on SIEBEL.

Earthtools.org has a webservice that you might want to look at.