---
title: "What are the 'effectiveAt' and 'effectiveFrom' timestamps?"
slug: "what-are-the-effectiveat-and-effectivefrom-timestamps"
tags: ["effectiveAt", "effectiveFrom", "bitemporal data", "effective date"]
updated: 2024-08-19T09:34:49Z
published: 2024-08-19T09:34:49Z
canonical: "support.lusid.com/what-are-the-effectiveat-and-effectivefrom-timestamps"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://support.lusid.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What are the 'effectiveAt' and 'effectiveFrom' timestamps?

For [bitemporal data](/v1/docs/what-is-bitemporal-data), the `effectiveAt` and `effectiveFrom` timestamps reflect the point in time at which a data item becomes valid in LUSID from a business perspective. [Find out about the asAt timestamp](/v1/docs/what-is-the-asat-timestamp).

- `effectiveAt` is the name of the timestamp field when you make a read or update request to LUSID, indicating that you want to retrieve or update data that is **effective at** the specified date.
- `effectiveFrom` is the name of the timestamp field that LUSID returns in response messages, indicating that the data is **effective from** the specified date.

The exact meaning of `effectiveAt` and `effectiveFrom` depend on the data in question. Examples include:

- The time a market price was published by an exchange.
- The date a credit rating changed for a legal entity.
- The date a corporate action should be applied.
- A transaction date.

An `effectiveAt` timestamp is supplied by a user when uploading data into LUSID, for example the price of a stock being 120p @10:30 on 1st February 2023 and 121p @10:40 pm on 1st February 2023.

If this data is loaded into the [LUSID Quote Store](/v1/docs/how-do-i-upload-a-market-price-or-fx-spot-rate-to-the-quote-store), a query for it would populate the `effectiveFrom` field with 2023-02-01T10:30:00Z or 2023-02-01T10:40:00Z (depending on the query used).