![Sun rise, set and twilight times calculated using a simple iterative scheme and implemented as a QBASIC program, an Excel spreadsheet using VBA and as a plain spreadsheet. Sun rise, set and twilight times calculated using a simple iterative scheme and implemented as a QBASIC program, an Excel spreadsheet using VBA and as a plain spreadsheet.](http://www.stargazing.net/kepler/sunsheet.gif)
Sun rise, set and twilight times calculated using a simple iterative scheme and implemented as a QBASIC program, an Excel spreadsheet using VBA and as a plain spreadsheet.
![time - How to calculate sunrise and sunset on on a given date and location? - Astronomy Stack Exchange time - How to calculate sunrise and sunset on on a given date and location? - Astronomy Stack Exchange](https://i.stack.imgur.com/Fb5cO.png)
time - How to calculate sunrise and sunset on on a given date and location? - Astronomy Stack Exchange
![the sun - About the formula for taking in count of the observer altitude in sunrise/sunset formula - Astronomy Stack Exchange the sun - About the formula for taking in count of the observer altitude in sunrise/sunset formula - Astronomy Stack Exchange](https://i.stack.imgur.com/OM8lD.png)