- Version: 2012-10-17 getting parsed as a date

[studds]

I've got a template:

Resources:
    Function:
        Type: 'AWS::Serverless::Function'
        Properties:
            CodeUri: code/
            Handler: code.handler
            Runtime: nodejs8.10
            Policies:
                - Version: 2012-10-17
                  Statement:
                      - Effect: Allow
                        Action: 'ses:SendRawEmail'
                        Resource: !Sub 'arn:aws:ses:*:*:identity/*'

When I read it and then write it out again, - Version: 2012-10-17 becomes - Version: 2012-10-17T00:00:00.000Z, which is invalid. - Version: '2012-10-17' is fine, but I'm hoping there's a way to make this more robust, and simply not parse the dates.

Any hints?