diff --git a/web-common/src/features/dashboards/url-state/invalid-url-state-variations.spec.ts b/web-common/src/features/dashboards/url-state/convertURLSearchParamsToExploreState.spec.ts
similarity index 86%
rename from web-common/src/features/dashboards/url-state/invalid-url-state-variations.spec.ts
rename to web-common/src/features/dashboards/url-state/convertURLSearchParamsToExploreState.spec.ts
index 2b3fe471f59d..c9a7a99e691a 100644
--- a/web-common/src/features/dashboards/url-state/invalid-url-state-variations.spec.ts
+++ b/web-common/src/features/dashboards/url-state/convertURLSearchParamsToExploreState.spec.ts
@@ -75,6 +75,28 @@ Unexpected " ".`,
     },
   },
 
+  {
+    title: "Time range only with default grain",
+    url: "http://localhost/explore/AdBids_explore?tr=7D",
+    errors: [],
+    entity: {
+      selectedTimeRange: {
+        interval: "TIME_GRAIN_DAY",
+        name: "7D",
+      } as DashboardTimeControls,
+    },
+  },
+  {
+    title: "Time range only with no default grain",
+    url: "http://localhost/explore/AdBids_explore?tr=inf",
+    errors: [],
+    entity: {
+      selectedTimeRange: {
+        interval: "TIME_GRAIN_HOUR",
+        name: "inf",
+      } as DashboardTimeControls,
+    },
+  },
   {
     title: "Invalid time ranges",
     url: "http://localhost/explore/AdBids_explore?tr=abc&grain=xyz",
@@ -131,7 +153,12 @@ Unexpected " ".`,
   },
 ];
 
-describe("Invalid Human readable URL State", () => {
+/**
+ * Has tests that call convertURLSearchParamsToExploreState directly.
+ * Unlike url-state-variations that tests actions on explore state.
+ * TODO: find a good unification of test cases so that a single set of cases run all variations.
+ */
+describe("direct convertURLSearchParamsToExploreState variations", () => {
   beforeEach(() => {
     metricsExplorerStore.remove(AD_BIDS_EXPLORE_NAME);
   });
diff --git a/web-common/src/features/dashboards/url-state/convertURLToExplorePreset.ts b/web-common/src/features/dashboards/url-state/convertURLToExplorePreset.ts
index 35ea0df51d5d..ee9ae56cbeb9 100644
--- a/web-common/src/features/dashboards/url-state/convertURLToExplorePreset.ts
+++ b/web-common/src/features/dashboards/url-state/convertURLToExplorePreset.ts
@@ -390,8 +390,9 @@ export function fromTimeRangesParams(
 
       if (grain && grain in V1TimeGrainToDateTimeUnit) {
         preset.timeGrain = V1TimeGrainToDateTimeUnit[grain];
-      } else {
-        errors.push(getSingleFieldError("time grain", grain ?? "undefined"));
+      } else if (grain) {
+        // Only throw error if grain is defined
+        errors.push(getSingleFieldError("time grain", grain));
       }
     } catch {
       // ignore