Does all true prophecy center on Israel and include a time frame?
Yes, all true prophecy centers on the nation of Israel. It usually, though not always, includes a time frame. God provides details and places them in time, as with the 490 years determined upon Israel in Daniel 9. The church age has no such prophecy.
Les teaches that all true prophecy centers on the nation of Israel, and usually, though not always, it comes within a time frame. He stresses that God puts the details out there and places them in time. For example, when Daniel 9 is reached, God says 490 years are determined upon the nation of Israel, and then fills in the details of what will happen in that period. That is prophecy. By contrast, the church age has nothing like that; there is no prophecy concerning the church. Les notes that we can see events getting ready for prophecy coming on the scene as the church approaches the end of the age of grace, but that is distinct from prophecy itself.