Originally Posted by
ChocolateFactory
Could it be dependent on your location?
In Europe, the week starts on Monday (which I, as a European, have to say makes a lot more sense to me), whereas in the US for example, it starts on Sunday.
It's quite common to see that difference when you open an airline's booking calendar on a European vs. the US website.
You could, of couse, try the BA website which caters to all tastes by offering both versions - you just need to look on different pages.
Back to ITA, I'm still seeing Sunday-Saturday, from the UK on a desktop with nothing special attached to it. I'd personally prefer Monday-Sunday, too.