azure-storage-common/src/Common/Internal/Validate.php
public static function isDateString($value, $name)
    {
        Validate::canCastAsString($value, 'value');

        try {
            new \DateTime($value);
            return true;
        } catch (\Exception $e) {
            throw new \InvalidArgumentException(
                sprintf(
                    Resources::ERROR_INVALID_DATE_STRING,
                    $name,
                    $value
                )
            );
        }
    }
public static function isDateString($value, $name)
    {
        Validate::canCastAsString($value, 'value');

        try {
            new \DateTime($value);
            return true;
        } catch (\Exception $e) {
            throw new \InvalidArgumentException(
                sprintf(
                    Resources::ERROR_INVALID_DATE_STRING,
                    $name,
                    $value
                )
            );
        }
    }
Validate if string is date formatted

@param string $value Value to validate
@param string $name  Name of parameter to insert in erro message

@throws \InvalidArgumentException

@return boolean