Image: Valtterri Bottas cuts through the evening dusk in his Williams
Image: Sebastian Vettel went quickest shortly before the lunch break
Image: The day began with the launch of the Haas team and their first F1 car
Image: Vettel impressed for Ferrari
Image: Hamilton waves to the fans during the lunch break
Image: Vettel was half a second clear at the top of the timesheets
Image: Hamilton was a centurion for laps completed in Barcelona
Image: Pascal Wehrlein debuted for Manor
Image: Jenson Button also completed more than a race distance in the McLaren
Image: Romain Grosjean missed much of the afternoon after a front-wing failure
Image: World champion Hamilton completes his day's work
The Sky Sports F1 Digital team will be providing live commentary from dawn until dusk on all four days of both Barcelona tests while Sky Sports News HQ will also deliver live updates from trackside.
