How did we figure these dates out? Is the process always the same? How certain are we that we are correct in these dates? How do we know exactly on what day significant events occurred in ancient history?

That being said, is there any logic behind the idea of a computer programmed to sort through historical documents from around the world to see if there were any errors in proposed dates? For example, if a government document from a certain date failed to meet certain historically relevant parameters set by another historical document known to be from the "same" date. I'm not sure if it makes much sense, but could this be attempted? Has this been attempted? If it hasn't or couldn't, why not? How much room for improvement is there on the accuracy of historical dates anyway?

TL;DR: WAY more questions than asked in my title, if you don't want to answer them, just read the first paragraph or answer the title.