For data which is modelled bi-temporally, the effectiveAt/effectiveFrom is the timestamp at which that piece of data became valid from from a business perspective.

  • effectiveAt is the name used for the field to specify the timestamp when you are making 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 used for the field that LUSID uses in response messages, indicating that the data is effective from the specified date


The exact meaning of the effectiveAt/effectiveFrom depends 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


EffectiveAts are supplied by the user when uploading data into LUSID, for example the price of the stock was 120p @10:30 on 1st January 2019, and 121p @10:40 pm on 1st January 2019. 

If this data was saved into the LUSID Quotes Store, a query for it would populate the effectiveFrom field with 2019-01-01T10:30:00z or 2019-01-01T10:40:00Z (depending on the query used).

For more details on the bi-temporal capability of LUSID see What is bi-temporal data?