Use this window to set the date and time to any point from 1000AD to 3000AD.
The "24 hour" checkbox switches between 24 hour mode and 12 hour AM/PM mode.
A checkbox for controlling daylight saving time (DST) will show only if the current location is not set for auto-DST. (See Set location window for why auto-DST may not be desirable for prior years if DST transition rules have changed.)
Pressing "OK" or "Apply" accepts the new date and time.
Pressing "Set to computer date/time" sets the local date/time
to the computer date/time.
Pressing "Cancel" rejects any changes.
Note: Night Vision assumes that the changeover
from the Julian calendar to the Gregorian calendar occurred
in October 1582 (as instituted by Pope Gregory XIII).
Ten days were removed, so that Thursday October 4, 1582 was
followed by Friday October 15, 1582. (The two calendar systems
differ by 3 days every 400 years.)
The transition to the Gregorian calendar occurred in different
years for different countries. (E.g. The transition for
England and its American colonies did not occur until September 1752,
when 11 days had to be removed (September 2 was followed by
September 14). The Gregorian date for
George Washington's birthday is February 22, 1732. The
corresponding Julian date is February 11, 1732. However, at the
time he was born the new year started on March 25, making the
local recorded date February 11, 1731.) Always use the Gregorian
date for dates after October 4, 1582.