I am trying to integrate a webhook system to the MongoDB Data API. In other words, I'm trying to insert (timeseries) data to via webhook.

The platform I'm working with has:
* inputs of a certain format, like dates are in ISO8601 format
* limited to JSON, no programmatic access to run JS code
* supports basic variable substitution, so I can insert string and numeric values into a JSON-formatted payload

Right now, I cannot insert my dates into a timeseries collection because they are a ISO8601 string and I cannot change the type inside the platform's template engine.

From the EJSON docs it looks like if the Data API can support Relaxed EJSON format for dates, I can substitute my date string into EJSON and get it to insert correctly to a timeseries collection.

Case Reference: #00889698