Question

they wrote, "it is time we thought about setting matter" change this in indirect speech

Answer 1

it is time that we thought about setting matter

Answer 2

The indirect speech of "they wrote it is time we thought about setting matter" will be "They wrote that it was time they had thought about setting that matter."

Indirect speech is a conversation where the original person committing the actions is absent, and the speech is conveyed by a third party to make it understandable to a separate hearer.