Claiming that the calculator wrong is the position of the skeptic. I'm the skeptic here. I don't need to prove a negative. You guys came to this thread with the claims that the internet calculators are right. It's your burden to prove those positive claims.
See: http://theflatearthsociety.org/wiki/index.php?title=Burden_of_Proof
I think I have an analogy for what is going on with the "you claim, no you claim" in this thread.
Imagine a person I'll call person 1 (represents Tom) suddenly stated that no cars could actually travel faster than 100 MPH. Well, someone we'll call person 2 calls person 1 out and says that many cars absolutly can go over 100 MPH. Person 1 says prove it. Person 2 says that any number of speedometers on cars could be shown to be indicating over 100 MPH while the car was driving. Person 1 says all speedometers are wrong, they are simply made up numbers and don't accurately reflect speed. Person 2 asks for proof of such a claim and person 1 say that he is not making a claim.
Person 1 says that person 2 is claiming speedometers are accurate and that cars can go over 100 MPH, and he is merely the skeptic and has no burden of proof to show that virtually every automobile speedometer in the world is wrong and that no car on Earth can go over 100 MPH. Person 1 says the burden of proof is on person 2 to prove his claims.
To me this seems like a complete misunderstanding of the "can't prove a negative" argument. You can't prove something doesn't exist if there is zero evidence either way. For instance, you can't ask someone to prove rainbow farting unicorns don't exist, because if they don't exist, then there will never be any evidence to use as proof of anything. Similarly, if someone claims unicorns that fart rainbows do exist, he would have the burden of proof when confronted by skeptics.
However, this is very different from claiming that internet Sunrise and Sunset calculators are wrong. Claiming that an existing device is inaccurate is a positive claim. It is something that could be tested and proof could be shown supporting the claim. To say you are a skeptic is fine. But simply labeling yourself as "skeptical" or "the skeptic" in regards to a certain issue doesn't relieve you from any burden of proof when you claim that something as widely used as Sunset/rise calculators are wrong. You aren't being asked to prove a negative. You aren't being asked to disprove something for which there is no evidence. You are being asked for any evidence which supports your claim that something which does exist, is widely used, and has been accurate each time it has been used by me, is not accurate.
If you don't want to provide any evidence or proof that's fine. I honestly don't care. Whether you have none, or simply can't be bothered, whatever. But the argument that you have nothing to prove because you aren't making any claims is silly to me.