This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
If you don't specify a locale, then it will use the default locale of your system. If that also happens to be US English (or some other language where the abbreviation for April is "Apr"), then ofcourse the results will be the same.