# UNITS

The `UNITS`

operator
converts an integer to an interval.

## Syntax

`expr` UNITS `qual`

where

`qual`can be one of:```
YEAR
MONTH
DAY
HOUR
MINUTE
SECOND
FRACTION(1-6)
```

`expr`is an integer expression.

## Usage

The `UNITS`

operator converts an integer expression to an `INTERVAL`

value expressed in a single
unit of time that you specify after the `UNITS`

keyword.

For the qualifiers

`YEAR`

, `MONTH`

, `DAY`

,
`HOUR`

and `SECOND`

, if the left-hand expression evaluates to a
decimal number, any fractional part is discarded before the `UNITS`

operator is
applied. However, when using `UNITS FRACTION`

, the expression can be a decimal number
where the integer part is interpreted as a number of seconds, and the decimal part as the fraction
of a
second:```
MAIN
DEFINE iv INTERVAL SECOND(9) TO FRACTION(5)
LET iv = 76242.77999 UNITS FRACTION
DISPLAY iv -- Displays " 76242.77999"
END MAIN
```

The

`UNITS`

operator can be used to compare `INTERVAL`

values. For
example, to check if an `INERVAL SECOND(9) TO SECOND`

is
negative:```
FUNCTION is_negative( iv INTERVAL SECOND(9) TO SECOND )
RETURN (iv < 0 UNITS SECOND )
END FUNCTION
```

`UNITS`

has
a higher precedence than any arithmetic or boolean operator. As a
result, a left-hand arithmetic expression that uses a `UNITS`

operator
must be enclosed in parentheses. For example, ```
10 + 20 UNITS
MINUTES
```

will be evaluated as `10 + (20 UNITS MINUTES)`

and
give a conversion error. It must be written ```
(10 + 20) UNITS
MINUTES
```

to get the expected result.

Because the difference between two

`DATE`

values is an integer count of days rather than an
`INTERVAL`

data type, you might want to use the `UNITS`

operator to
convert such differences explicitly to `INTERVAL`

values:```
MAIN
DEFINE d DATE
LET d = TODAY + 200
DISPLAY (d - TODAY) UNITS DAY
END MAIN
```