code: func StartTime(startTime time.Time) RescanOption {
  	return func(ro *rescanOptions) {
  		ro.startTime = startTime
  	}
  }
docs: // StartTime specifies the start time. The time is compared to the timestamp of
  // each block, and the rescan only begins once the first block crosses that
  // timestamp. When using this, it is advisable to use a margin of error and
  // start rescans slightly earlier than required. The rescan uses the latter of
  // StartBlock and StartTime.