in lib/lambda/save-to-s3/index.ts [36:45]
function generateS3Key(event: any): string {
const {id, detail} = event;
const paddingChar = "0";
const d = new Date(parseInt(detail.ts, 10));
const year = d.getFullYear();
const month = (d.getMonth() + 1).toString().padStart(2, paddingChar);
const day = d.getDate().toString().padStart(2, paddingChar);
return `${year}/${month}/${day}/${id}`;
}