All Our Yesterdays
All Our Yesterdays (AOY) is the time travel supplement from Last Unicorn Games. While apparently set during the latter part of the Dominion War (judging by references to both the Cardassian Union and the Dominion) the book is designed to work in any of the Star Trek games: ST: TOS¸ ST:TNG¸ ST: DS9. This presumably also works for ST: V.
The book details time travel¸ and alternate time lines. It goes into much detail coving the Federation Department of Temporal Investigations¸ and lays out a handful of new equipment¸ advantages¸ disadvantages¸ and so fourth. The book generally success in its goals.