The Explorer: Windows' "Short Date Format" Scare

I've gotten maybe 50 e-mails in the last week about a "new" Y2K issue--maybe you got one, too. The heart of the letter is something like this:

Every copy of Windows in the world has default settings that will make it FAIL on Jan. 1, 2000!!!! I'm not kidding!!!! Check for yourself!!!! PASS THIS LETTER ON!!!!!

TEST:
Click on "START"
Click on "SETTING"
Click on "CONTROL PANEL"
Double click on "REGIONAL SETTINGS" icon
Click on the "DATE" tab at the top of the page.

Where it says, "Short Date Sample," look and see if it shows a "two digit" year (yy). That is the default setting for Windows 95, Windows 98 and NT.

This date RIGHT HERE is the date that feeds application software and WILL NOT roll over in the year 2000. It will roll over to 00.

Click on the "SHORT DATE STYLE" pull-down menu and select the option that shows, mm/dd/yyyy. (Be sure your selection has four Y's showing and not two.)

Click on "APPLY" and then click on "OK" at the bottom.

Alas, this note is mostly wrong--in fact, Microsoft calls it an outright hoax. The worst part of the e-mail is that it fails to distinguish between date calculations and date displays. The "date format picker" above affects only how Windows displays dates and interprets the way you type in dates. It tells you nothing about the underlying software calculations or about your PC's date-keeping hardware.

If your PC hardware is Y2K compliant and if you're running a newer version of Windows and/or have applied the Y2K patches available (for free) from the Microsoft site, Windows will calculate Y2K dates correctly regardless of whether or not the date is displayed in two- or four-digit format.

What's more, with a compliant PC and the Y2K patches, even if you still allow two-digit date displays, you'll be fine. The year "00" will be correctly interpreted as 2000, "01" will correctly mean 2001 and so on. In fact, with the Y2K patches applied, Windows will interpret any two-digit dates this way:

00 to 29: Windows will infer a "20" before the digits; "15" will mean 2015, for example.
30 to 99: Windows will infer a "19" before the digits; "85" will mean 1985, for example.

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