Support parsing "hours" like 1am or 10pm

go/remind/remind.go

	if len(parts) == more {
		return t, nil
	} else if len(parts) == more+2 && parts[more] == "at" {
		h, err := parseHours(parts[more+1])
		if err != nil {
			return t, err
		}
		t = truncateHours(t)
		return t.Add(h), nil
	} else if len(parts) == more+3 && parts[more] == "at" &&
		(parts[more+2] == "am" || parts[more+2] == "pm") {
		h, err := parseHours(parts[more+1] + parts[more+2])
		if err != nil {
			return t, err
		}
		t = truncateHours(t)
		return t.Add(h), nil
	}
	return t, fmt.Errorf("unknown date spec '%s' (unexpected)", s)
		return t.AddDate(n*years, n*months, n*days)
	}
}
func parseHours(s string) (time.Duration, error) {
	var d time.Duration
	isPm := false
	switch {
	case strings.HasSuffix(s, "am"):
		s = s[0 : len(s)-2]
	case strings.HasSuffix(s, "pm"):
		isPm = true
		s = s[0 : len(s)-2]
	default:
		return d, fmt.Errorf("unknown hours '%s'", s)
	}
	n, err := strconv.Atoi(s)
	if err != nil {
		return d, err
	}
	if n < 1 || n > 12 {
		return d, fmt.Errorf("invalid hour: %d (must be between 1 and 12)", n)
	}
	if isPm {
		n += 12
	}
	return time.Duration(n) * time.Hour, nil
}
func truncateHours(t time.Time) time.Time {
	return t.Truncate(time.Hour).Add(-time.Duration(t.Hour()) * time.Hour)
}

go/remind/remind_test.go

	}{
		{"today", now},
		{"tomorrow", now.AddDate(0, 0, 1)},
		//"tomorrow at 3am"
		{"tomorrow at 3am", truncateHours(now).AddDate(0, 0, 1).Add(3 * time.Hour)},
		{"in 3 days", now.AddDate(0, 0, 3)},
		{"in a month", now.AddDate(0, 1, 0)},
		{"in 3 months", now.AddDate(0, 3, 0)},
		{"in 3 weeks", now.AddDate(0, 0, 3*7)},
		//"2016-09-28",
		//"3pm",
		//"in 4 days at 10 pm",
		{"in 4 days at 10 pm", truncateHours(now).AddDate(0, 0, 4).Add(22 * time.Hour)},
	}
	for _, example := range examples {