My setting for a time server seems to be stable. I did the setting in the Date and Time of System Preferences. However, if I click on the clock in the upper right of the screen and choose "Open Date & Time..." nothing happens at all. Almost like this choice is inoperative.
As far as the second problem is concerned (ie. the Open Date and Time menu command not working) I had a similar problem with the Open Dock Preferences menus not working and I managed to fix it. I expect the same fix will work for other Menu commands to open preferences.
Basically, your system doesn't know which application to use to open preference panes. To fix it, follow thse steps:-
Open up Mac Help in the Help menu
Search for "date and time"
Click on 1 of the options like "I can't set the date and time"
You should see a link at the bottom saying "Open date and time preferences for me".
Click this link
You should then get an error message that the system doesn't know which application to use and asking you to choose one.
Select the System Preferences app (it will be greyed out at first, but if you turn off the "Recommended Applications" choice in the pop-up menu, you should be able to choose it.
Voila! All your menus to open preference panes should work now.
Thanks for the suggestion, EWHAN. I followed your instructions and linked the help link to the System Preferences application. So now Mac Help works for Date and Time, but the link from the Date/Time Menu drop down still justs sits passively when Open Data & Time... are selected.