The first question is: why does it matter? For one thing, if your company reports revenues on a year from--say--July 1 to June 30, your results will look very different than your competitor that reports from January 1 to December 31. Every company I know of reports their quarterly numbers quarter-over-quarter and year-over-year, of course. For what that's worth, that quarterly information becomes a common denominator. But the quarterly nuances are lost in the annual reports.
For example, TRUMPF had a rousing year ending June 30, with about 50% growth measured in both dollars or euros. That's fantastic, but keep in mind that TRUMPF doesn't report quarterly numbers. It doesn't have to report numbers at all, since it's a private company. The very good fiscal year followed two years of declines. Most companies reporting on calendar years only had one down year: 2009. So, TRUMPF looked like it was doing worse than everybody for two years, and now it looks like it outperformed. In fact, it's about the same--it just reports on different calendar.
The other question is: how can it make that much difference? In this recession, the four worst quarters all fell in 2009. So any company reporting on the calendar year saw a really bad 2009 and only upward results after that. TRUMPF simply split the bad quarters, spreading the bad quarters over two fiscal years.
There is one more nuance to this. People are most familiar and emotional about the metrics that they know best, not necessarily the ones that I have to use. For example, salespeople often speak of orders and pricing for sales that haven't happened yet, since that is where they are working with their customers. But those orders and pricing may be unrepresentative of orders earlier this year.
Another example is that people rejoice over recent good news and panic over recent bad news--even if it is stripped of its context. Part of my job is to put the context back.