Agent schedule is created by the system itself. All agents in one node are accessible under one agent schedule. Hence for every node there exists one Agent Schedule. If not present, the system creates Agent Schedule. Please find below content from an article that I found useful. This should help.
When Process Commander starts, the system looks for all the Agents rules. For each of these rules, the system looks for one Agent Schedule instance for each node.
If there is not an Agent Schedule instance present for a node, the system creates one by copying information from the associated Agents rule. Thus, if a system has five nodes, then for the Pega-RULES Agents rule, there will be five Pega-RULES Agent Schedule data instances.