Why the different date formats?

[Wander]

I remember hearing that it had to do with pilgrimages.
As the adage goes - all roads lead to Rome. Therefore, as you were travelling to Rome to visit the Vatican/Pope, you had to be on the left (in latin - sinister). The right side (remembering the orientation that roads led to Rome) could be used by those who had made their pilgrimage because they were no longer 'sinister'.

As said by John, above, in the wake of the American Revolution they sought to overturn the Old Ways (tm) and so changed the side to drive on, and spelling (actually, I believe they had a go at inventing a whole new language so they could move away from the perfidious English, but it never caught on). Although they did stick with Imperial measurements - metric was too complicated, presumably.

 

[Scottieoutdoors]

makes sense, I thought it odd that no matter which side of the road you drive on, if two cars hit each other head on or side swiped the chances were both drivers would be killed as they were so close to one and other, on the other hand it made it easy to transfer goods or messages as they passed, the other thing of course is that passengers could get in from the sidewalk. Not too sure about the sword explanation, sitting on the left would be an advantage, as the sword could hang in free space, sitting on the right as we do, the sword would have to cope with the seat and would no doubt cause problems, sword bearers would no doubt benefit from riding a bike.......lol

I believe the sword thing was more to do with the days of horse riding, or horse riders, rather than coach/wagon drivers.