---
title: Temporal Reasoning
description: "Time-aware memory retrieval for Mem0 Platform v3 so queries like 'last week', 'upcoming', and 'right now' return the right memories."
badge: "v3"
---

Some memories matter because of **when** they happened, not just because they sound similar. Temporal Reasoning lets Mem0 Platform v3 understand time-aware queries and return the most contextually appropriate results.

<Info>
  **Use Temporal Reasoning when…**
  - Users ask questions like "what happened last week?" or "what do I have coming up?"
  - Your app stores both past events and future plans for the same person
  - You want time-aware retrieval without building your own date-parsing layer
</Info>

<Warning>
  Temporal Reasoning is a **Mem0 Platform v3** feature. It is not available on OSS memory stores or older Platform endpoints.
</Warning>

## Configure access

Confirm your `MEM0_API_KEY` is set and that you are using the v3 Platform client:

```python
from mem0 import MemoryClient

client = MemoryClient(api_key="your-api-key")
```

## How it works

When a memory describes an event, a future plan, or an ongoing state, Temporal Reasoning recognizes the time context so the right results surface at search time.

A query like `what did I do last week?` should return a completed past event: not an upcoming appointment and not a stable fact that hasn't changed. Temporal Reasoning handles that distinction automatically.

### Memory types Temporal Reasoning handles

| Type | What it represents | Example |
| --- | --- | --- |
| Dated occurrence | Something that happened at a known time | "I finished the Q1 review on March 10, 2025." |
| Future plan | A future commitment or scheduled item | "I have a dentist appointment on March 18, 2025." |
| Ongoing state | A fact that remains true over time | "I am the product lead at Acme Corp." |
| Relationship | A durable connection between people or entities | "Priya manages Jordan." |
| Preference | A stable preference or habit | "I prefer morning meetings." |

Results come back in the normal search response shape: Temporal Reasoning affects ranking, not the response format.

## Configure it

Temporal Reasoning is enabled by default for all v3 searches and writes. There is no per-request toggle.

Two parameters give you precise control when you need it:

- `timestamp` on `add()`: anchors an imported memory to the time it actually happened, rather than the time it was added to Mem0
- `reference_date` on `search()`: resolves relative phrases like `last week` against a fixed point in time

<CodeGroup>
```python Python
from datetime import datetime, timezone
from mem0 import MemoryClient

client = MemoryClient(api_key="your-api-key")

# Import a historical memory anchored to when it happened
client.add(
    [{"role": "user", "content": "I finished the Q1 review on March 10, 2025."}],
    user_id="jordan",
    timestamp=int(datetime(2025, 3, 10, tzinfo=timezone.utc).timestamp()),
)

# Search with a relative query anchored to a known date
results = client.search(
    "what did I do last week?",
    filters={"user_id": "jordan"},
    reference_date="2025-03-21T00:00:00Z",
)
```

```javascript JavaScript
import { MemoryClient } from "mem0ai";

const client = new MemoryClient({ apiKey: "your-api-key" });

// Import a historical memory anchored to when it happened
await client.add(
  [{ role: "user", content: "I finished the Q1 review on March 10, 2025." }],
  {
    userId: "jordan",
    timestamp: Math.floor(new Date("2025-03-10T00:00:00Z").getTime() / 1000),
  }
);

// Search with a relative query anchored to a known date
const results = await client.search("what did I do last week?", {
  filters: { user_id: "jordan" },
  referenceDate: "2025-03-21T00:00:00Z",
});
```
</CodeGroup>

<Tip>
  `reference_date` is especially useful in automated tests and demos because it makes relative phrases like `last week` resolve consistently every time.
</Tip>

## Supported query patterns

<AccordionGroup>
  <Accordion title="Historical questions">
    Examples: `last week`, `last month`, `in March 2025`, `on 2025-03-10`
  </Accordion>
  <Accordion title="Upcoming questions">
    Examples: `upcoming`, `next week`, `tomorrow`, `what do I have coming up?`
  </Accordion>
  <Accordion title="Current-state questions">
    Examples: `right now`, `currently`, `where do I work now?`
  </Accordion>
  <Accordion title="As-of questions">
    Examples: `as of March 2025`, `where was I living as of 2024?`
  </Accordion>
  <Accordion title="Duration questions">
    Examples: `how long have I lived here?`, `since when have I worked there?`
  </Accordion>
</AccordionGroup>

## Verify the feature is working

- Run a temporal search with a time-aware query (e.g., "what did I do last week?") and confirm the memory that fits the time window ranks first.
- Use `reference_date` in test queries so relative phrases resolve consistently across runs.
- For backfilled data, pass `timestamp` on `add()` to confirm the memory reflects the right point in time.

## Best practices

- Use explicit dates in source conversations when events or plans matter temporally.
- Pass `timestamp` during historical imports so the ingestion time does not become the only time anchor.
- Scope searches with `filters` so time-aware ranking operates inside the right user boundary.
- Use `reference_date` in automated tests and reproducible demos.

<CardGroup cols={1}>
  <Card title="Memory Timestamps" icon="calendar" href="/platform/features/timestamp">
    Anchor imported memories to when they actually happened.
  </Card>
</CardGroup>

<Snippet file="get-help.mdx" />