If the author and public instances are not using the same time, you may see the following error when you publish content:
The error is coming either from
info.magnolia.publishing.command.PublicationCommand when using the Publishing module or from
info.magnolia.cms.exchange.ExchangeException when using the Activation module.
To resolve this issue, check the system time (server time) on both instances. Configure the servers to use Network Time Protocol (NTP) so that they could use the same time and stay in sync.
If you are still getting the error, then on your public instance(s) configure:
With the Publishing module in use, a higher
Node name Valuemodulespublishing-coreconfigpublicationDelayTolerance
With the Activation module in use, a higher
Node name ValuemodulesactivationconfigactivationDelayTolerance
In both cases the properties allow for a time difference between the instances. The default value is 30,000 milliseconds (30 seconds).