}
	return FromTimestamp(t.Add(duration)), nil
}

// dateDiff computes the difference between two times in terms of the
// `timePart` which can be years, months, days, hours, minutes or
// seconds. For difference in years, months or days, the time part,
// including timezone is ignored.
func dateDiff(timePart string, ts1, ts2 time.Time) (*Value, error) {
	if ts2.Before(ts1) {

			return -1, nil
		}
	}

	// Try to parse as a number of months
	if !strings.HasSuffix(s, "m") {
		return -1, errors.New("unknown format")
	}

	months, err := strconv.Atoi(strings.TrimSuffix(s, "m"))
	if err != nil {
		return -1, err
	}

	if months < minimumBitrotCycleInMonths {
		return -1, fmt.Errorf("minimum bitrot cycle is %d month(s)", minimumBitrotCycleInMonths)
	}

func msDosTimeToTime(dosDate, dosTime uint16) time.Time {
	return time.Date(
		// date bits 0-4: day of month; 5-8: month; 9-15: years since 1980
		int(dosDate>>9+1980),
		time.Month(dosDate>>5&0xf),
		int(dosDate&0x1f),

		// time bits 0-4: second/2; 5-10: minute; 11-15: hour
		int(dosTime>>11),
		int(dosTime>>5&0x3f),
		int(dosTime&0x1f*2),

		// Testcase index 20
		{30 * 24 * time.Hour, "my_download_url", "1 month before the latest release"},
		{31 * 24 * time.Hour, "my_download_url", "1 month before the latest release"},
		{61 * 24 * time.Hour, "my_download_url", "2 months before the latest release"},
		{360 * 24 * time.Hour, "my_download_url", "1 year before the latest release"},

			query:      `SELECT date_diff(month, '2010-01-01T', '2010-05T') FROM S3Object LIMIT 1`,
			wantResult: `{"_1":4}`,
		},
		{
			name:       "date_diff_month_oney",
			query:      `SELECT date_diff(month, '2010T', '2011T') FROM S3Object LIMIT 1`,
			wantResult: `{"_1":12}`,
		},
		{
			name:       "date_diff_month_neg",
			query:      `SELECT date_diff(month, '2011T', '2010T') FROM S3Object LIMIT 1`,

	if isFirstRow {
		intA, okI := a.ToInt()
		if okI {
			v.setInt(intA)
			return nil
		}
		floatA, _ := a.ToFloat()
		v.setFloat(floatA)
		return nil
	}

	intV, ok1i := v.ToInt()
	intA, ok2i := a.ToInt()
	if ok1i && ok2i {
		result := intV
		if !isMax {
			if intA < result {
				result = intA
			}
		} else {
			if intA > result {
				result = intA
			}

		"sum(2 + s.id)",
		"sum(t)",
		"avg(s.id[1])",
		"coalesce(s.id[1], 2, 2 + 3)",

		"cast(s as string)",
		"cast(s AS INT)",
		"cast(s as DECIMAL)",
		"extract(YEAR from '2018-01-09')",
		"extract(month from '2018-01-09')",

		"extract(hour from '2018-01-09')",
		"extract(day from '2018-01-09')",
		"substring('abcd' from 2 for 2)",
		"substring('abcd' from 2)",
		"substring('abcd' , 2 , 2)",

	Quantity  *Operand     `parser:" @@ \",\""`
	Timestamp *PrimaryTerm `parser:" @@ \")\""`
}

// DateDiffFunc represents the DATE_DIFF function
type DateDiffFunc struct {