Docusign Insight - What is the default Date Format?

Insight uses ISO date format hence when searching for a termination date, for example, you can use:

TerminationDate:"2018-09-08T12:00:00Z"

When searching for a date range the following format can be used:

TerminationDate:[2018-09-07T00:00:00Z TO 2018-09-08T00:00:00Z]