How to use 'incorporated_to' parameter

Hi, I want to use the incorporated_to parameter in the advanced search which takes a ‘date’ value, but what exactly is a ‘date’? This isn’t clear in the documenation. How do I structure a request that can provide valid data to this parameter? Thanks.

I hope this line will help, it accepts dates formatted as YYYY-MM-DD:
https://api.company-information.service.gov.uk/advanced-search/companies?incorporated_to=2022-05-30