I must admit I've never understood why some country's use mm/dd/yyyy. It seems odd, I'm from the uk. As with Fahrenheit and Celsius, when I see Americans talking about it being 60 degrees I haven't a clue what temp it is and have to convert, it's what they are used to using and we are used to using Celsius but there never seems to be a standard measurement anymore. Now weights, why do Americans use pounds? For an example, I'm watching deadliest catch and they mention one boat has pulled in 250,000 pounds.... I then have to do a calculation to convert it to tons as I can't visualise what 250,000 pounds is. 125 tons I can. But then France uses KM and we use miles, again I'm not sure why some country's choose to use one style of measurement over another you would think if everything was the same standard it would make life easier?