In fact charts like https://secure.phabricator.com/fact/chart/?y1=N%3A* dates are wrongly localized, without respect for browser configuration.
**Browser configuration:**
Firefox returned "**en**,en-us;q=0.8,fr;q=0.6,fr-be;q=0.4,fr-fr;q=0.2" as HTTP_ACCEPT_LANGUAGE.
Keyboard and OS languages are french.
**Expected behavior:**
English l10n
**Current behavior:**
French l10n
**Note:**
This is probably an upstream bug for Raphael.