Answer number 6 :)

I'm not the only person that knows the answer,Silvia knows it. For that reason we've worked together. The first part of your enigma is: We can change our timetable, in Prime Meridian( is the meridian at which longitude is defined to be 0°), it's obvious. The second part is Sandford Fleming. He linked the anti-meridian of Greenwich (now 180°). He suggested that standard time zones could be used locally, but they were subordinate to his single world time. For this reason, the navigator was easier. Finally, the last answer is the Cutty Sark. Not a long time back, clippers were known by the Cutty Sark, built at 1870, that was a business ship until 1922. Until 2007, the Cutty Sark was a floating museum, but on 20th May of 2007 it was burnt. Today, the police continues without finding the answer of this fire.