Should have used S3 and a datetime-based access policy. Eg

  {
    "Version": "2012-10-17",
    "Statement": [
      {
        "Sid": "Statement1",
        "Effect": "Allow",
        "Action": [
          "s3:GetObject"
        ],
        "Resource": "arn:aws:s3:::obr-leaky-bucket/myfirst.pdf",
        "Condition": {
          "DateGreaterThan": {
            "aws:CurrentTime": "2025-11-26T12:30:00"
          }
        }
       }
    ]
  }