From d0c373390ce16965f1562caf519750e555d26ee6 Mon Sep 17 00:00:00 2001
From: Andrew Paseltiner <apaseltiner@google.com>
Date: Wed, 28 May 2025 11:15:35 -0400
Subject: [PATCH 1/3] Make stored-impression lifetime field a duration

---
 api.bs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/api.bs b/api.bs
index 321390f..b424af0 100644
--- a/api.bs
+++ b/api.bs
@@ -860,7 +860,7 @@ The [=impression store=] is a [=set=] of [=impression|impressions=]:
     or `undefined` if the API was invoked by the [=impression site=].
 <dfn>Conversion Sites</dfn>: The [=set=] of [=conversion sites=] that were passed to <a>saveImpression()</a>.
 <dfn>Timestamp</dfn>: The time at which <a>saveImpression()</a> was called.
-<dfn>Lifetime</dfn>: The number of days an [=/impression=] remains eligible for attribution, either from the call to <a>saveImpression()</a>, or a [=/user agent=]-defined limit.
+<dfn>Lifetime</dfn>: The [=duration=] an [=/impression=] remains eligible for attribution, either from the call to <a>saveImpression()</a>, or a [=/user agent=]-defined limit.
 <dfn>Histogram Index</dfn>: The histogram index passed to <a>saveImpression()</a>.
 </pre>
 </div>

From 97e4b3899b3cc952ef616cdc72d724e16bf6be61 Mon Sep 17 00:00:00 2001
From: Andrew Paseltiner <apaseltiner@google.com>
Date: Wed, 28 May 2025 11:21:26 -0400
Subject: [PATCH 2/3] Exclude expired impressions from common matching logic

---
 api.bs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/api.bs b/api.bs
index b424af0..563859f 100644
--- a/api.bs
+++ b/api.bs
@@ -1414,6 +1414,9 @@ To perform <dfn>common matching logic</dfn>, given
 1.  [=set/iterate|For each=] |impression| in the [=impression store=] for the |epoch|:
 <!-- TODO: Clarify "for the |epoch|" -->
 
+    1.  If |now| - |impression|'s [=impression/lifetime=] is after |impression|'s
+        [=impression/timestamp=], [=iteration/continue=].
+
     1.  If |now| - |lookbackDays| is after |impression|'s [=impression/timestamp=],
         [=iteration/continue=].
 

From a972958bc219cd2a589a2240dd3c3bcf5748120b Mon Sep 17 00:00:00 2001
From: Andrew Paseltiner <apaseltiner@google.com>
Date: Thu, 29 May 2025 08:05:05 -0400
Subject: [PATCH 3/3] Update api.bs

Co-authored-by: Martin Thomson <mt@lowentropy.net>
---
 api.bs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/api.bs b/api.bs
index 563859f..e99375f 100644
--- a/api.bs
+++ b/api.bs
@@ -1414,8 +1414,8 @@ To perform <dfn>common matching logic</dfn>, given
 1.  [=set/iterate|For each=] |impression| in the [=impression store=] for the |epoch|:
 <!-- TODO: Clarify "for the |epoch|" -->
 
-    1.  If |now| - |impression|'s [=impression/lifetime=] is after |impression|'s
-        [=impression/timestamp=], [=iteration/continue=].
+    1.  If |now| is after |impression|'s [=impression/timestamp=] plus |impression|'s
+        [=impression/lifetime=], [=iteration/continue=].
 
     1.  If |now| - |lookbackDays| is after |impression|'s [=impression/timestamp=],
         [=iteration/continue=].