How to make time
Most supporters will no doubt be aware that as the fleet progress around the Earth they will move through several time zones. Celestially speaking noon is the time at which the sun passes the observers meridian and as such is at its ‘highest’ point. When referring to time zones the suns position is slightly different at noon depending on the exact location of the observer. The best example of this is actually in the Canary Islands where the sun rises and sets a little over an hour later than at Greenwich each day. This is simply because the Islands are West of Greenwich and as they are in the same time zone, by definition the sun must rise and set later.
As everybody will know, there are 24 hours to each day and as the earth is 360 degrees, by travelling 15 degrees along the lines of longitude the time changes by one hour. Again, for example, La Gomera is 17 degrees West of Greenwich, so the sun rises a little over an hour later each day.
The crews will move through 4 time zones on their way to the finish line to the South of Antigua (GMT -4) and most are currently at GMT -1. Crews will pass into and out off the time zones at the following longitudes:
GMT -2 from 22° 30’W to 37° 30’W
GMT -3 from 37° 30’W to 52° 30’W
GMT -4 from 52° 30’W to 67° 30’W
So when the progress page publishes a crews position, check their westing against the list above to find what time zone they will be in.
Should one wish to check time closely, look at the mileage each crew makes West each day. As 15 degrees of longitude equates 1 hour of time, then 1 degree (which equals 60 nautical miles) of Longitude is equal to four minutes of time, therefore it could be suggested that if crew travels 60 miles west in 1 day then that crews day is extended by 4 minutes and will therefore be slightly longer than 24 hours…they are making time.