Tools
Interactive ways to use the data behind this site. There's one tool so far, described honestly below rather than padded out with a roadmap of things that don't exist yet.
Available tools
Birthstone Finder
Enter a birth date and it returns what every system says about it, side by side, rather than picking a single answer: four monthly lists (a historical list, the US 1912 standard, the UK 2013 standard, and the current US trade list) plus two zodiac lists (the traditional tropical zodiac and the modern jewelry-trade zodiac). Dates that fall within a day of a zodiac sign boundary are flagged as cusp dates, with both signs shown. The same data is also laid out as static tables below the tool, so it works with JavaScript disabled.
Open Birthstone Finder →