This read-only TimeInterval object reports how many seconds remain before the newest active key in this TEK association expires, complementing cwrBpiRmTEKExpiresOld, and it likewise reads zero if there are no active keys. Together the old and new expiry values let an admin see exactly where a given TEK association sits in its rekey cycle from the master's perspective. For example, both values reading zero simultaneously would indicate that particular TEK association currently has no valid key at all, a condition worth immediate investigation.