From 48c86c867a128c666473dcb70c31d557cdb2b0db Mon Sep 17 00:00:00 2001
From: Andrew Paseltiner <apaseltiner@google.com>
Date: Fri, 22 Aug 2025 08:25:40 -0400
Subject: [PATCH] Remove lookback-based early return from common matching logic

---
 api.bs              | 5 -----
 impl/src/backend.ts | 8 --------
 2 files changed, 13 deletions(-)

diff --git a/api.bs b/api.bs
index 8f29ff2..0b81156 100644
--- a/api.bs
+++ b/api.bs
@@ -1693,11 +1693,6 @@ To perform <dfn>common matching logic</dfn>, given
 
 1.  Let |matching| be an [=set/is empty|empty=] [=set=].
 
-1.  Let |earliestEpoch| be the result of calling [=get the current epoch=],
-    passing |topLevelSite| and (|now| − |options|' [=validated conversion options/lookback=]).
-
-1.  If |earliestEpoch| is greater than |epoch|, return |matching|.
-
 1.  [=set/iterate|For each=] |impression| in the [=impression store=]:
 
     1.  Let |impressionEpoch| be the result of calling [=get the current epoch=],
diff --git a/impl/src/backend.ts b/impl/src/backend.ts
index 1b33ae4..4a06ea3 100644
--- a/impl/src/backend.ts
+++ b/impl/src/backend.ts
@@ -357,14 +357,6 @@ export class Backend {
   ): Set<Impression> {
     const matching = new Set<Impression>();
 
-    const earliestEpoch = this.#getCurrentEpoch(
-      topLevelSite,
-      now.subtract(lookback),
-    );
-    if (earliestEpoch > epoch) {
-      return matching;
-    }
-
     for (const impression of this.#impressions) {
       const impressionEpoch = this.#getCurrentEpoch(
         topLevelSite,