setDate() {
    var dateRegEx = new RegExp(this.config.dateParser);
    if (this.date) {
      this.datetime = getDatetime(this.date);
      this.date = this.config.dateFormat(this.datetime);
    } else if (dateRegEx.test(this.url)) {
      this.date = dateRegEx.exec(this.url);
      this.datetime = getDatetime(this.date);
      this.date = this.config.dateFormat(this.datetime);
    }
  }
Set file date.
@method
@description
Check if file has date in front matter otherwise use the date
in the filename.