By default, the site replication is happening 24/7. Based on the site bandwidth consideration, this can be changed. For example, if it's a slow link, it is best to set the replication in after operation hours and in lunch hours. It will control the replication traffic impact on slow links and allow the organization to use the link bandwidth for other mission critical traffic. It's important to evaluate the consequences of changing the replication schedule. If you add/modify objects and policies, those will not replicate between sites unless they match replication intervals and the replication schedule.

In order to set up the site links, we can use the New-ADReplicationSiteLink cmdlet:

New-ADReplicationSiteLink -Name "London-Canada" -SitesIncluded LondonSite,CanadaSite -Cost 205 -ReplicationFrequencyInMinutes 30 -InterSiteTransportProtocol IP

The preceding command creates a new site link called London-Canada and it includes LondonSite and CanadaSite. The site cost is set to 205, and the replication intervals are set to every 30 minutes. Its transport protocol is set to IP.

We can create and also modify the settings using the Active Directory Sites and Services MMC:

We can change the replication schedule using the -ReplicationSchedule option or GUI. In order to change it using GUI, click on the Change Schedule... button. Then in the window, you can change the replication schedule. In this demo, I changed the replication to happen Monday to Friday from 6 a.m. to 10 a.m.: