diff --git a/src/options.js b/src/options.js
index 51043a854e..dc1b1c842b 100644
--- a/src/options.js
+++ b/src/options.js
@@ -426,7 +426,7 @@ export function maybeNiceInterval(interval, type) {
 }
 
 export function isTimeInterval(t) {
-  return isInterval(t) && typeof t?.floor === "function" && t.floor() instanceof Date;
+  return isInterval(t) && typeof t?.floor === "function";
 }
 
 export function isInterval(t) {
diff --git a/test/options-test.js b/test/options-test.js
index e2c0634f6e..4eedaec3e7 100644
--- a/test/options-test.js
+++ b/test/options-test.js
@@ -1,5 +1,5 @@
 import {assert, it} from "vitest";
-import {identity, isNumericString, valueof} from "../src/options.js";
+import {identity, isNumericString, valueof, isTimeInterval} from "../src/options.js";
 import {isYearInteger, isYearIntegers} from "../src/options.js";
 
 it("isYearInteger returns true for integers in [1500, 2500]", () => {
@@ -74,6 +74,12 @@ it("isNumericString only checks the first present value", () => {
   assert.strictEqual(isNumericString(["notstring", "42"]), false);
 });
 
+it("isTimeInterval returns true for interval-like objects with a date floor", () => {
+  assert.strictEqual(isTimeInterval({range: () => [new Date()], floor: () => new Date()}), true);
+  assert.strictEqual(isTimeInterval({range: () => [0], floor: () => 0}), false);
+  assert.strictEqual(isTimeInterval({range: () => [0]}), false);
+});
+
 it("valueof returns nullish value", () => {
   assert.strictEqual(valueof([], null), null);
   assert.strictEqual(valueof([], undefined), undefined);