diff --git a/src/duration.ts b/src/duration.ts
index 74cb017..ee82e28 100644
--- a/src/duration.ts
+++ b/src/duration.ts
@@ -119,6 +119,72 @@ export function elapsedTime(date: Date, precision: Unit = 'second', now = Date.n
   )
 }
 
+const durationRoundingThresholds = [
+  Infinity, // Year
+  11, // Month
+  28, // Day
+  21, // Hour
+  55, // Minute
+  55, // Second
+  900, // Millisecond
+]
+
+export function relativeTime(
+  date: Date,
+  precision: Unit = 'second',
+  nowTimestamp: Date | number = Date.now(),
+): [number, Intl.RelativeTimeFormatUnit] {
+  let precisionIndex = unitNames.indexOf(precision)
+  if (precisionIndex === -1) {
+    precisionIndex = unitNames.length
+  }
+  const now = new Date(nowTimestamp)
+  const sign = Math.sign(date.getTime() - now.getTime())
+  const dateWithoutTime = new Date(date)
+  dateWithoutTime.setHours(0)
+  dateWithoutTime.setMinutes(0)
+  dateWithoutTime.setSeconds(0)
+  dateWithoutTime.setMilliseconds(0)
+  const nowWithoutTime = new Date(now)
+  nowWithoutTime.setHours(0)
+  nowWithoutTime.setMinutes(0)
+  nowWithoutTime.setSeconds(0)
+  nowWithoutTime.setMilliseconds(0)
+  if (
+    precisionIndex >= 4 && // At least hour.
+    (dateWithoutTime.getTime() === nowWithoutTime.getTime() ||
+      Math.abs(date.getTime() - now.getTime()) < 1000 * 60 * 60 * 12)
+  ) {
+    const difference = Math.round(((date.getTime() - now.getTime()) / 1000) * sign)
+    let hours = Math.floor(difference / 3600)
+    let minutes = Math.floor((difference % 3600) / 60)
+    const seconds = Math.floor(difference % 60)
+    if (hours === 0) {
+      if (seconds >= durationRoundingThresholds[5]) minutes += 1
+      if (minutes >= durationRoundingThresholds[4]) return [sign, 'hour']
+      if (precision === 'hour') return [0, 'hour']
+      if (minutes === 0 && precisionIndex >= 6) return [seconds * sign, 'second']
+      return [minutes * sign, 'minute']
+    } else {
+      if (hours < 23 && minutes >= durationRoundingThresholds[4]) hours += 1
+      return [hours * sign, 'hour']
+    }
+  }
+  const days = Math.round(((dateWithoutTime.getTime() - nowWithoutTime.getTime()) / (1000 * 60 * 60 * 24)) * sign)
+  const months = date.getFullYear() * 12 + date.getMonth() - (now.getFullYear() * 12 + now.getMonth())
+  if (
+    precisionIndex >= 2 && // At least week.
+    (months === 0 || days <= 26)
+  ) {
+    if (precision === 'week' || days >= 6) return [Math.floor((days + 1) / 7) * sign, 'week']
+    return [days * sign, 'day']
+  }
+  if (precision !== 'year' && Math.abs(months) < 12) {
+    return [months, 'month']
+  }
+  return [date.getFullYear() - now.getFullYear(), 'year']
+}
+
 interface RoundingOpts {
   relativeTo: Date | number
 }
diff --git a/src/relative-time-element.ts b/src/relative-time-element.ts
index 068183d..90bf4c9 100644
--- a/src/relative-time-element.ts
+++ b/src/relative-time-element.ts
@@ -1,4 +1,4 @@
-import {Duration, elapsedTime, getRelativeTimeUnit, isDuration, roundToSingleUnit, Unit, unitNames} from './duration.js'
+import {Duration, Unit, elapsedTime, isDuration, relativeTime, roundToSingleUnit, unitNames} from './duration.js'
 const HTMLElement = globalThis.HTMLElement || (null as unknown as typeof window['HTMLElement'])
 
 export type DeprecatedFormat = 'auto' | 'micro' | 'elapsed'
@@ -172,15 +172,16 @@ export class RelativeTimeElement extends HTMLElement implements Intl.DateTimeFor
     return duration.abs().toLocaleString(locale, {style})
   }
 
-  #getRelativeFormat(duration: Duration): string {
+  #getRelativeFormat(date: Date): string {
     const relativeFormat = new Intl.RelativeTimeFormat(this.#lang, {
       numeric: 'auto',
       style: this.formatStyle,
     })
+    let [int, unit] = relativeTime(date, this.precision)
     const tense = this.tense
-    if (tense === 'future' && duration.sign !== 1) duration = emptyDuration
-    if (tense === 'past' && duration.sign !== -1) duration = emptyDuration
-    const [int, unit] = getRelativeTimeUnit(duration)
+    if ((tense === 'future' && int < 0) || (tense === 'past' && int > 0)) {
+      ;[int, unit] = [0, 'second']
+    }
     if (unit === 'second' && int < 10) {
       return relativeFormat.format(0, this.precision === 'millisecond' ? 'second' : this.precision)
     }
@@ -453,7 +454,7 @@ export class RelativeTimeElement extends HTMLElement implements Intl.DateTimeFor
     if (format === 'duration') {
       newText = this.#getDurationFormat(duration)
     } else if (format === 'relative') {
-      newText = this.#getRelativeFormat(duration)
+      newText = this.#getRelativeFormat(date)
     } else {
       newText = this.#getDateTimeFormat(date)
     }
diff --git a/test/duration.ts b/test/duration.ts
index 3b35600..3fcb146 100644
--- a/test/duration.ts
+++ b/test/duration.ts
@@ -1,5 +1,12 @@
 import {assert} from '@open-wc/testing'
-import {applyDuration, Duration, elapsedTime, getRelativeTimeUnit, roundToSingleUnit} from '../src/duration.ts'
+import {
+  Duration,
+  applyDuration,
+  elapsedTime,
+  getRelativeTimeUnit,
+  relativeTime,
+  roundToSingleUnit,
+} from '../src/duration.ts'
 import {Temporal} from '@js-temporal/polyfill'
 
 suite('duration', function () {
@@ -228,6 +235,259 @@ suite('duration', function () {
     }
   })
 
+  suite('relativeTime', function () {
+    const relativeTests = [
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        expected: [0, 'second'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:01',
+        expected: [1, 'second'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T11:59:59',
+        expected: [-1, 'second'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:58',
+        expected: [1, 'minute'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T11:59:02',
+        expected: [-1, 'minute'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:05:00',
+        expected: [5, 'minute'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T11:55:00',
+        expected: [-5, 'minute'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:58:00',
+        expected: [1, 'hour'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T11:02:00',
+        expected: [-1, 'hour'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:54:55',
+        expected: [1, 'hour'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T11:05:05',
+        expected: [-1, 'hour'],
+      },
+      {
+        now: '2024-10-15T00:00:00',
+        date: '2024-10-15T23:59:59',
+        expected: [23, 'hour'],
+      },
+      {
+        now: '2024-10-15T23:59:59',
+        date: '2024-10-15T00:00:00',
+        expected: [-23, 'hour'],
+      },
+      {
+        now: '2024-10-15T18:00:00',
+        date: '2024-10-16T00:00:00',
+        expected: [6, 'hour'],
+      },
+      {
+        now: '2024-10-15T00:00:00',
+        date: '2024-10-14T18:00:00',
+        expected: [-6, 'hour'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-16T00:00:00',
+        expected: [1, 'day'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-14T23:00:00',
+        expected: [-1, 'day'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-25T12:00:00',
+        expected: [1, 'week'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-05T12:00:00',
+        expected: [-1, 'week'],
+      },
+      {
+        now: '2024-10-01T12:00:00',
+        date: '2024-10-21T12:00:00',
+        expected: [3, 'week'],
+      },
+      {
+        now: '2024-10-21T12:00:00',
+        date: '2024-10-01T12:00:00',
+        expected: [-3, 'week'],
+      },
+      {
+        now: '2024-10-05T12:00:00',
+        date: '2024-11-01T12:00:00',
+        expected: [1, 'month'],
+      },
+      {
+        now: '2024-10-01T12:00:00',
+        date: '2024-09-04T12:00:00',
+        expected: [-1, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-12-15T12:00:00',
+        expected: [2, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-08-15T12:00:00',
+        expected: [-2, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2025-01-15T12:00:00',
+        expected: [3, 'month'],
+      },
+      {
+        now: '2025-01-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        expected: [-3, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00Z',
+        date: '2025-09-15T12:00:00Z',
+        expected: [11, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00Z',
+        date: '2023-11-15T12:00:00Z',
+        expected: [-11, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00Z',
+        date: '2025-10-15T12:00:00Z',
+        expected: [1, 'year'],
+      },
+      {
+        now: '2024-10-15T12:00:00Z',
+        date: '2023-10-15T12:00:00Z',
+        expected: [-1, 'year'],
+      },
+      {
+        now: '2024-10-15T12:00:00Z',
+        date: '2029-01-15T12:00:00Z',
+        expected: [5, 'year'],
+      },
+      {
+        now: '2024-01-15T12:00:00Z',
+        date: '2019-10-15T12:00:00Z',
+        expected: [-5, 'year'],
+      },
+
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        precision: 'minute',
+        expected: [0, 'minute'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        precision: 'hour',
+        expected: [0, 'hour'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        precision: 'day',
+        expected: [0, 'day'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        precision: 'week',
+        expected: [0, 'week'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        precision: 'month',
+        expected: [0, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:00',
+        precision: 'year',
+        expected: [0, 'year'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:00:50',
+        precision: 'minute',
+        expected: [0, 'minute'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T12:50:00',
+        precision: 'hour',
+        expected: [0, 'hour'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-15T22:00:00',
+        precision: 'day',
+        expected: [0, 'day'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-20T12:00:00',
+        precision: 'week',
+        expected: [0, 'week'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-10-31T12:00:00',
+        precision: 'month',
+        expected: [0, 'month'],
+      },
+      {
+        now: '2024-10-15T12:00:00',
+        date: '2024-12-15T12:00:00',
+        precision: 'year',
+        expected: [0, 'year'],
+      },
+    ]
+    for (const {
+      now,
+      date,
+      precision = 'second',
+      expected: [val, unit],
+    } of relativeTests) {
+      test(`relativeTime(${date}, ${precision}, ${now}) === [${val}, ${unit}]`, () => {
+        assert.deepEqual(relativeTime(new Date(date), precision, new Date(now)), [val, unit])
+      })
+    }
+  })
+
   suite('roundToSingleUnit', function () {
     const roundTests = new Set([
       ['PT20S', 'PT20S'],
diff --git a/test/relative-time.js b/test/relative-time.js
index 0d13096..c5a81c8 100644
--- a/test/relative-time.js
+++ b/test/relative-time.js
@@ -452,7 +452,7 @@ suite('relative-time', function () {
       time.setAttribute('tense', 'past')
       time.setAttribute('datetime', '2023-01-01T00:00:00Z')
       await Promise.resolve()
-      assert.equal(time.shadowRoot.textContent, '11 years ago')
+      assert.equal(time.shadowRoot.textContent, '10 years ago')
     })
 
     test('rewrites from now past datetime to minutes ago', async () => {
@@ -499,7 +499,7 @@ suite('relative-time', function () {
       time.setAttribute('tense', 'past')
       time.setAttribute('datetime', '2023-06-01T00:00:00Z')
       await Promise.resolve()
-      assert.equal(time.shadowRoot.textContent, '4 months ago')
+      assert.equal(time.shadowRoot.textContent, '3 months ago')
     })
 
     test('rewrites from last few days of month to smaller last month', async () => {
@@ -1180,7 +1180,7 @@ suite('relative-time', function () {
         datetime: '2022-11-13T15:46:00.000Z',
         format: 'relative',
         precision: 'month',
-        expected: 'this month',
+        expected: 'next month',
       },
       {
         datetime: '2022-11-13T15:46:00.000Z',