lib/ThreeScaleAuthorizeResponse.php
public function getPeriodStart() {
    if (is_null($this->parsedPeriodStart)) {
      $this->parsedPeriodStart = strtotime($this->periodStart);
    }

    return $this->parsedPeriodStart;
  }
public function getPeriodStart() {
    if (is_null($this->parsedPeriodStart)) {
      $this->parsedPeriodStart = strtotime($this->periodStart);
    }

    return $this->parsedPeriodStart;
  }
Start of the current period of the usage limit, as unix timestamp.

@return int (unit timestamp)