When did tree ear go to songdo?

Tree-ear, the protagonist in the novel "A Single Shard" by Linda Sue Park, travels to Songdo in search of a skilled potter named Min. This journey occurs later in the story, as Tree-ear aims to deliver a message about a pottery commission. The exact time of his journey is not specified, but it takes place after he has spent time learning about pottery in the village of Ch'ulp'o.