Mac OS and the year 2000

TOPIC

This article contains three question and answer pairs dealing with the Mac OS and the year 2000.

1. Will the Mac OS have a problem with dates in the year 2000?
2. Why can I not set the date in the Date & Time control panel past the year 2019?
3. Question: Is the year 2000 a leap year?

DISCUSSION

Question: Will the Mac OS have a problem with the year 2000?

Answer: No. The Mac OS has always correctly handled dates between January 1, 1904 and February 6, 2040. The current Mac OS date and time utilities handle all dates between 30,081 B.C. and 29,940 A.D. All applications and system software which use the supplied Mac OS date and time utilities will have no problems with the year 2000. The only possible issues would come if an application does not use the routines supplied by the Mac OS for manipulating dates and times. If you believe you have such an application, please contact the manufacturer of that application for an update.

Question: Why can I not set the date in the Date & Time control panel past the year 2019?

Answer: The Date & Time control panel constrains the year to the range 1920 to 2019. This was done because the original Macintosh System 6 General control panel only displayed a 2-digit year. A programmer can set the date beyond 2019 by calling a Mac OS supplied routine. Apple expects to release a revised Date & Time control panel as part of Mac OS 8.

Question: Is the year 2000 a leap year?

Answer: The rule for leap years is that all years divisible by 4 are leap years, except those years divisible by 100. The exception is that years divisible by 400 are leap years. This means that 1800 and 1900 were not leap years, but the year 2000 is a leap year.