diff --git a/ts/lib/tslib/time.ts b/ts/lib/tslib/time.ts
index b560f1546..05bc45563 100644
--- a/ts/lib/tslib/time.ts
+++ b/ts/lib/tslib/time.ts
@@ -177,28 +177,18 @@ export function dayLabel(daysStart: number, daysEnd: number): string {
                 daysStart,
                 daysEnd: daysEnd - 1,
             });
+        } else if (daysEnd <= 0) {
+            // Past: [-10, -5) -> "5-9 days ago"
+            return tr.statisticsDaysAgoRange({
+                daysStart: Math.abs(daysEnd),
+                daysEnd: Math.abs(daysStart) - 1,
+            });
         } else {
-            // For bins that cross or end at day 0, we need special handling
-            if (daysEnd > 0) {
-                // Bin crosses day 0: show from 0 to the oldest day (exclusive of endDay)
-                // If bin is [-5, 1), we want "0-4 days ago"
-                return tr.statisticsDaysAgoRange({
-                    daysStart: 0,
-                    daysEnd: -daysStart - 1,
-                });
-            } else {
-                // Bin is entirely in the past: show from newest to oldest
-                // For a bin [startDay, endDay), to show consecutive ranges like "0-4", "5-9", "10-14",
-                // we use endDay as the start of the range
-                // The bin width is daysEnd - daysStart, so daysEnd = daysStart + (width - 1)
-                // Example: bin [-10, -5) has width 5, should show "5-9 days ago"
-                const binWidth = Math.abs(daysEnd - daysStart);
-                const daysStartAbs = Math.abs(daysEnd);
-                return tr.statisticsDaysAgoRange({
-                    daysStart: daysStartAbs,
-                    daysEnd: daysStartAbs + binWidth - 1,
-                });
-            }
+            // Crosses zero: [-5, 1) -> "0-4 days ago"
+            return tr.statisticsDaysAgoRange({
+                daysStart: 0,
+                daysEnd: Math.abs(daysStart) - 1,
+            });
         }
     }
 }
diff --git a/ts/routes/graphs/reviews.ts b/ts/routes/graphs/reviews.ts
index 8cb221886..a32089a3e 100644
--- a/ts/routes/graphs/reviews.ts
+++ b/ts/routes/graphs/reviews.ts
@@ -234,17 +234,10 @@ export function renderReviews(
     }
 
     function tooltipText(d: BinType, cumulative: number): string {
+        // Convert bin boundaries [x0, x1) for dayLabel
+        // If bin ends at 0, treat it as crossing zero so day 0 is included
         const startDay = Math.floor(d.x0!);
-        // If bin ends at 0, treat it as including day 0 (so use 1 as endDay for dayLabel)
-        // For negative bins, use the bin end directly (dayLabel will handle the conversion)
-        let endDay: number;
-        if (d.x1! === 0) {
-            endDay = 1;
-        } else if (d.x1! < 0) {
-            endDay = d.x1!;
-        } else {
-            endDay = Math.ceil(d.x1!);
-        }
+        const endDay = d.x1! === 0 ? 1 : d.x1!;
         const day = dayLabel(startDay, endDay);
         const totals = totalsForBin(d);
         const dayTotal = valueLabel(sum(totals));