Yamm module embed a server-side scheduler which will allow you to send
scheduled synchronization orders to clients.
This scheduler is implemented using a DataSync job (may be a simple cron
run in future, but always prefer the DataSync job if you can use it).
The job is simple, it sends a push order to all registered clients that
have are in activated state.
To use it, enable the Yamm scheduler module, on the server Drupal
instance.
To schedule the job execution, refers to DataSync module documentation
on how to set up a scheduled job.