When I run this script for this particular date on my M1Mac Mini 11.2.3, the aDate’s month is July. On my MacBook Pro (15-inch, 2018) 11.2.3 it is June. Am I doing something obviously wrong?
set theDate to current date
set theYear to 2000
set theMonth to 6
set theDay to 1
tell theDate to set {its month, its day, its year, its hours, its minutes, its seconds} to {theMonth, theDay, theYear, 0, 0, 0}
display dialog theDate as text
-->Saturday, July 1, 2000 at 00:00:00