diff --git a/src/app/api/gamification/achievements/route.ts b/src/app/api/gamification/achievements/route.ts
index fc4efe2e0..b04f4a72e 100644
--- a/src/app/api/gamification/achievements/route.ts
+++ b/src/app/api/gamification/achievements/route.ts
@@ -278,7 +278,9 @@ function getOnTimePerfectDaySeries(
         scheduledDate,
       );
 
-      if (timing !== "on_time") {
+      // v1.4.34 IW-C — `early` is also a compliant bucket (dose taken
+      // within the 3h pre-window grace), so it preserves a perfect day.
+      if (timing !== "on_time" && timing !== "early") {
         isPerfectDay = false;
         break;
       }
diff --git a/src/app/api/medications/[id]/compliance/route.ts b/src/app/api/medications/[id]/compliance/route.ts
index 5eb4f1c93..ebc2c11d5 100644
--- a/src/app/api/medications/[id]/compliance/route.ts
+++ b/src/app/api/medications/[id]/compliance/route.ts
@@ -80,6 +80,7 @@ export const GET = apiHandler(
       let onTime = 0;
       let late = 0;
       let veryLate = 0;
+      let early = 0;
 
       for (const evt of takenEvents) {
         if (medication.schedules.length === 0) {
@@ -111,7 +112,13 @@ export const GET = apiHandler(
           dayStart, // the scheduled date
         );
 
+        // v1.4.34 IW-C — `early` is the new compliant bucket; it counts
+        // alongside `onTime` for the heatmap so a proactive logger reads
+        // green. The classifier still emits a distinct `"early"` value
+        // for downstream consumers that want to differentiate; the
+        // separate counter is surfaced on the daily entry below.
         if (timing === "on_time") onTime++;
+        else if (timing === "early") early++;
         else if (timing === "late") late++;
         else veryLate++;
       }
@@ -120,9 +127,10 @@ export const GET = apiHandler(
         expected: schedulesPerDay,
         taken: takenEvents.length,
         skipped: dayEvents.filter((e) => e.skipped).length,
-        onTime,
+        onTime: onTime + early,
         late,
         veryLate,
+        early,
       };
     }
 
diff --git a/src/lib/medications/scheduling/cadence.ts b/src/lib/medications/scheduling/cadence.ts
index 332b59ed6..34683770b 100644
--- a/src/lib/medications/scheduling/cadence.ts
+++ b/src/lib/medications/scheduling/cadence.ts
@@ -70,8 +70,8 @@ const WEEK_MS = 7 * DAY_MS;
  * Match window for pairing an actual intake event to an expected
  * dose: +/- 12 hours around the slot's center.
  *
- * Rationale: the existing classifyIntakeTiming uses a 1-hour grace
- * before the window + ~2-hour late tolerance after. For cadence
+ * Rationale: the existing classifyIntakeTiming uses a 3-hour grace
+ * around the window + a configurable late tolerance after. For cadence
  * visualisation we want a wider matching radius so users who logged a
  * weekly shot a day late still see it paired with that week's slot
  * (and the slot reads `taken`, not `missed` followed by an "extra").