I had to redact a bunch of this ask’s spoilery bits but I think I managed — in essence, I’ve gotten a lot of asks about where the epilogue of Clockwork Princess fits into the timeline of TMI.
Here’s the basic timeline of the TMI books:
CoB: takes place in August 2007, the year the book was published.
CoA: begins in very early September 2007- a few days to a week after CoB ends.
CoG: begins in September, about 1 week after CoA ends. The whole book takes place in 1.5-2 weeks. It is mentioned that the leaves on trees are beginning to turn fall colors.
CoFA: begins in Mid-October (Halloween decorations are up, Simon mentions the month) and ends around the third or fourth week of October. In CoFA, it is also mentioned that Clary has been training to fight demons for 7 weeks.
CoLS: The prologue is set in late October. The first chapter begins two weeks later, in the 2nd week of November.
October had 5 weeks in 2007. Here’s a link to a 2007 calendar:
The Clockwork Princess prologue takes place in 2008.
We don’t know when in 2008, but we do know enough to know it takes place after the events of City of Lost Souls. It is either during or after the events of City of Heavenly Fire.
As for Bro Z, he appears in City of Fallen Angels and City of Lost Souls. It is explained in City of Fallen Angels that he was among the few Silent Brothers who was not in the Silent City when Valentine attacked, and therefore survived.
So yes, basically, the epilogue of Clockwork Princess takes place in the future of the characters in City of Lost Souls. You can search it for clues about Heavenly Fire if you want. :)