TZ-DB
A static database of timezone labels and both standard and DST offset values for each; as scraped from wikipedia.
var tz = ; tzzones407;//=> Europe/London tztz'Europe/London';//=> { std: '+00:00', dst: '+01:00' } tztz'America/New_York';//=> { std: '-05:00', dst: '-04:00' }
Recompiling is easy:
cd tz-dbnode src/compile.js