For a while, Time.gov was one of the poster children for Lazlo (https://en.wikipedia.org/wiki/OpenLaszlo), one of the more interesting cross platform toolsets back in the day (akin to Haxe nowadays). You can see the LZW (lzx) files in older versions of the site in Archive.org Wayback (2007 or so onward). The team translated their purely Java portion into Lazlo then cross compiled into swf for Flash. So, it went from CGI (perl) to Java to Flash to HTML (still via Laszlo) to a few revisions here and there to work around browser changes to finally this latest revamp. See some background in https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50644 from 2007.