Delete My Activity from your Google Account older than 9 moonths.

google-my-activity-deletion.js

Date.prototype.getUnixTime = function() {
  return this.getTime()/1000|0;
};
Date.prototype.getUnixMicroUnixTime = function() {
  return this.getUnixTime()*1000000;
};

var date = new Date();
date.setMonth(date.getMonth() - 9);

var google_bulkdelta = date.getUnixMicroUnixTime() - 1;

'https://myactivity.google.com/api/select-delete?bulkdelete=1&log=custom&bulkdelta=' + google_bulkdelta;