Date & Time Control Panel in Mac OS 8 (released in 1997) will only let you set a Mac’s date to a range between January 1, 1920 and December 31, 2019
There is a utility that will allow you to set the date and time on your Classic Mac all the way up until the last second: SetDate
Simply type in the date and time (in military format)
Download SetDate (17KB)
Allows setting the date/time through 2042. The stock System 7 Date & Time control panel has problems with current dates. This allows manually setting the date & time through 2042 when deeper problems arise
Military Date Time Group
In US military messages and communications the format is DD HHMMZ MON YY.
Although occasionally seen with spaces, it can also be written as a single string of characters.
Example 1: 091630Z JUL 11 represents (Jul) 09 16:30 Jul 2011 (UTC).
Example 2: 141608Z Dec 19 represents (Dec) 14 16:08, Dec 2019 (UTC)
tested on SE/30
mac system 7.0 no problem since only dozens (tens) and units are displayed
tested on IIci
mac system 7.1 > patch
mac os 8 > patch