Set date & time automatically, Not Working

I know this is not really a xojo question, but, I have a xojo web app running on a Mac Mini with OSX 10.9.5. The app is using an API that requires a timestamp with each post and the timestamp on our system must be within 30 seconds of theirs. I am finding that the Mac Mini’s clock will not be within 30 seconds of the actual time after a week or so. When I go into the system settings under Date & Time, the check box is checked that says “Set date and time automatically”" and the drop down box is set to “Apple Americas/US (”. It seems when I go to this screen, the time synchronizes itself automatically without me clicking anything but I am obviously wanting it to stay in sync. Any ideas? I’m preferring NOT to upgrade the OS at this time but if that is the only option that I guess we can.One more thing, right now we are leaving a user session logged in. I think we can discontinue doing that if it will help.

Updating the os might be the way to go especially if you will have to do it eventually anyway. If you really want to avoid that, check this link for some possible solutions. Looks like editing some of the launchdaemons might work.