Hi @Ben Wright,
I believe that rudderstack send in data through our HTTP v2 API. With this API, Amplitude uses the key “time” in the JSON event object to determine event time.
time | Optional. The timestamp of the event in milliseconds since epoch. If time isn't sent with the event, then it's set to the request upload time. |
I checked the raw data for one of your projects, and saw the “time” field was passed with valid values. An example value is: 1685034104000.
Could you please check with rudderstack what values they are passing to Amplitude for the “time” key? Thanks.