I built one -- taking nothing more sophisticated than what's available for download off of Investing.com [OHLC and volume] data, and then sorting things into buckets.
I experimented just using screen shots, you quickly realise, there is no such thing as 2 days the same ever, more hassle than worth!!
Nice job! Was this in Excel only...?
Screen shots, huh?
You're more wrong than you know.
Yep a Library of Screen shots, compiled over a few months, waste of time that was.
You need data. Not screenshots.
Disagree, easiest way with no data feed to look for patterns, it failed so maybe not.

Let's say it's Thursday before the Payroll numbers at the beginnin of a new month. Is there software that can look back over several years and consolidate the price action for a given security coming into and out of the Payroll number? Be nice to have some stats before making a trade.
I know this is the despised nearest neighbor algorithm. I'd still like to see how a security has behaved in the past in specific settings.
Some practical constraints: 1) only compare the security with its own history; 2) sample the security's price action from the same time of day.