One of the neat little design touches of Windows 7 that changed as a result of usage analysis was the calendar that is shown when you click the clock on your system tray. User feedback taught product designers that in previous versions of Windows, users would often go into the "Date & Time Properties" dialog box, not to set the date but just to see the calendar - eg what date is it 3 weeks from now?, or what day is Christmas Day .?
Of course, in earlier Windows versions, if you changed the date by clicking on another month/year, and hit the OK button, it would actually change the system date. not necessarily a good thing. In Windows 7, the default behaviour is to just show you the calendar, and easily allow you to jump between months, years, even decades.
Of course, you could just use Outlook, but a) not everyone uses Outlook all the time (the poor non-productive fools!) and b) it's usually just quick & easy to click on the taskbar to check a date. If you are in Outlook, did you know that you can type in expressions into any date field - eg the Start date of a meeting. "3 weeks on Tuesday" , "next Friday", "in 60 days", "7d", "Christmas 2013" . there are loads of variants to try.
If you're a habitual jet-setter, are planning a holiday in foreign climes or just want to know the time in another part of the world, you can also add multiple clocks in Windows 7. Click on the Date/Time part of the system tray, click on Change date and time settings. and then the Additional Clocks tab.
Sure beats those £2,000 "executive wall clocks" that feature in the back pages of in-flight magazines.