**What were you trying to accomplish?** ## Expected Behavior AWSDateTime - An extended ISO 8601 date and time string in the format YYYY-MM-DDThh:mm:ss.sssZ. ## Current Behavior AWSDateTime is not including the millisecond part `sss`. ## Possible Solution Generate timestamps to include the milliseconds ## Steps to Reproduce (for bugs) ```python3 > print(aws_datetime()) 2021-07-02T17:09:47Z ```` ## Environment * **Powertools version used**: 1.17.0 * **Packaging format (Layers, PyPi)**: PyPi * **AWS Lambda function runtime:** Python 3.8