Probably going to be lengthy post - sorry -- I've been working to configure ten new MacBook Pro's to our AD domain. Through many days of pain, I've determined there's some sort of date/time problem with version 10.12.4 of Sierra. I can consistently reproduce the problem. If I leave the OS at 10.12.3 (shipped version), the problem doesn't occur. Other details: Location services are turned off Time zone is properly set. Option to "Set Date and Time automatically" is set, using default Apple Time Servers. Here's the pattern: New out of box. Create an admin account, apply all updates. So far so good. Join the computer to our (AD 2003) domain (please, no comments on AD 2003; we're working on it) Reboot computer. It will now have a date of 12/31/2037, and time varies depending on time of day. If I go in to the Date/Time control panel, and unlock the padlock, the date / time immediately corrects itself. As those of you familiar with AD know, correct date/time is critical. I don't want to turn off option to automatically set date/time for DST reasons. The users getting these computers aren't day-to-day Mac users. Anyone else encounter this, and find a solution (aside from not using 10.12.4)? Thanks in advance for any tips.