Some months ago our friends at Phyber setup a few more servers for the NTP Pool project. Over the last months I've been moving services to them to make the NTP Pool infrastructure run faster and with more redundancy.
The old RRD based graphs (deprecated a few months ago) are still being used a bit, but really don't play well with having multiple servers. Over the last week I changed the site to generate the offset and score graphs via the same D3.js based system and PhantomJS.
As you can see the score and the offset log are in one graph now, where the old graphs unhelpfully had separate charts for that. If you are using both on an internal dashboard, please update to just use the offset.png version.
Downloading the .rrd files don't work anymore, but instead you can fetch the recent monitoring data in JSON format (in addition to the old CSV format), for example http://www.pool.ntp.org/scores/18.104.22.168/json. If you really want the data in RRD format, you can easily take either of these to generate it yourself. Both log formats support a "since" parameter (taking a unix timestamp, for example since= 1339132534) to only show data points after that time.