Date, Timestamp, and Interval Operators
The arithmetic operators +, , *, and / are binary operators.
Operator  Description  Notes 

+ 
Addition 
interval + interval = interval interval + datetime = datetime datetime + interval = datetime 
 
Subtraction 
interval  interval = interval datetime  interval = datetime ( <datetime>  <datetime> ) Date, Timestamp, and Interval Operators <interval qualifier> = interval 
* 
Multiplication 
interval * numeric = interval numeric * interval = interval 
/ 
Division 
interval / numeric = interval 
Examples
Example  Operation  Result 

1 
INTERVAL '1' DAY + INTERVAL '3' DAY 
INTERVAL '4' DAY 
2 
INTERVAL '1' DAY + INTERVAL '3 4' DAY TO HOUR 
INTERVAL '+4 04' DAY TO HOUR 
3 
INTERVAL '1' DAY  INTERVAL '3 4' DAY TO HOUR 
INTERVAL '2 04' DAY TO HOUR 
4 
INTERVAL '1' YEAR + INTERVAL '34' YEAR TO MONTH 
INTERVAL '+404' YEAR TO MONTH 
5 
2 * INTERVAL '3 4' DAY TO HOUR 
INTERVAL '6 8' DAY TO HOUR 
6 
INTERVAL '3 4' DAY TO HOUR / 2 
INTERVAL ' 1 14' DAY TO HOUR 
In the example 3, '3 4 DAY means 3 days and 4 hours, so the result in that row means 24 hours minus 76 hours, resulting in minus 52 hours, which is a negative 2 days and 4 hours.
Example 4 uses TO MONTH rather than TO HOUR, so the INTERVAL specified as '34' means 3 years and 4 months, or 40 months.
In example 6, the "/2" applies to the INTERVAL '3 4', which is 76 hours, half of which is 38, or 1 day and 14 hours.
Further Examples of Interval Operations
Streaming SQL also supports subtracting two datetimes, giving an interval. You specify what kind of interval you want for the result, as shown following:
(<datetime>  <datetime>) <interval qualifier>
The following examples show operations that can be useful in Amazon Kinesis Data Analytics applications.
Example 1 – Time Difference (as minutes to the nearest second or as seconds)
values cast ((time '12:03:34'  time '11:57:23') minute to second as varchar(8)); ++ EXPR$0 ++ +6:11 ++ 1 row selected ............... 6 minutes, 11 seconds or values cast ((time '12:03:34'  time '11:57:23') second as varchar(8)); ++ EXPR$0 ++ +371 ++ 1 row selected
Example 2 – Time Difference (as minutes only)
values cast ((time '12:03:34'  time '11:57:23') minute as varchar(8)); ++ EXPR$0 ++ +6 ++ 1 row selected ............... 6 minutes; seconds ignored. values cast ((time '12:03:23'  time '11:57:23') minute as varchar(8)); ++ EXPR$0 ++ +6 ++ 1 row selected ............... 6 minutes
Example 3 – TimetoTimestamp Difference (as days to the nearest second) Invalid
values cast ((time '12:03:34'timestamp '20040429 11:57:23') day to second as varchar(8)); Error: From line 1, column 14 to line 1, column 79: Parameters must be of the same type
Example 4 – Timestamp difference (as days to the nearest second)
values cast ((timestamp '20040501 12:03:34'  timestamp '20040429 11:57:23') day to second as varchar(8)); ++ EXPR$0 ++ +2 00:06 ++ 1 row selected ............... 2 days, 6 minutes ............... Although "second" was specified above, the varchar(8) happens to allow only room enough to show only the minutes, not the seconds. The example below expands to varchar(11), showing the full result: values cast ((timestamp '20040501 12:03:34'  timestamp '20040429 11:57:23') day to second as varchar(11)); ++ EXPR$0 ++ +2 00:06:11 ++ 1 row selected ............... 2 days, 6 minutes, 11 seconds
Example 5 – Timestamp Difference (as days to the nearest second)
values cast ((timestamp '20040501 1:03:34'  timestamp '20040429 11:57:23') day to second as varchar(11)); ++ EXPR$0 ++ +1 13:06:11 ++ 1 row selected ............... 1 day, 13 hours, 6 minutes, 11 seconds values cast ((timestamp '20040501 13:03:34'  timestamp '20040429 11:57:23') day to second as varchar(11)); ++ EXPR$0 ++ +2 01:06:11 ++ 1 row selected ............... 2 days, 1 hour, 6 minutes, 11 seconds
Example 6 – Timestamp Difference (as days)
values cast ((timestamp '20040501 12:03:34'  timestamp '20040429 11:57:23') day as varchar(8)); ++ EXPR$0 ++ +2 ++ 1 row selected ............... 2 days
Example 7 – Time Difference (as days)
values cast ((date '20041202 '  date '20031201 ') day as varchar(8)); Error: Illegal DATE literal '20041202 ': not in format 'yyyyMMdd' .............. Both date literals end with a space; disallowed. values cast ((date '20041202'  date '20031201 ') day as varchar(8)); Error: Illegal DATE literal '20031201 ': not in format 'yyyyMMdd' .............. Second date literal still ends with a space; disallowed. values cast ((date '20041202'  date '20031201') day as varchar(8)); ++ EXPR$0 ++ +367 ++ 1 row selected ............... 367 days
Example 8 – Not Supported (Simple Difference of Dates)
If you don't specify "day" as the intended unit, as shown following, the subtraction is not supported.
values cast ((date '20041202'  date '20031201') as varchar(8)); Error: From line 1, column 15 to line 1, column 51: Cannot apply '' to arguments of type '<DATE>  <DATE>'. Supported form(s): '<NUMERIC>  <NUMERIC>' '<DATETIME_INTERVAL>  <DATETIME_INTERVAL>' '<DATETIME>  <DATETIME_INTERVAL>'
Why Use "as varchar" in Conversion Examples?
The reason for using the "values cast (<expression> AS varchar(N))" syntax in the examples above is that while the SQLline client used above (with Amazon Kinesis Data Analytics running) does return an interval, JDBC does not support returning that result so as to display it. Therefore, that "values" syntax is used to see/show it.
If you close the Amazon Kinesis Data Analytics (with a !kill command) or if you don't start it before running SQLline, then you can run the sqllineEngine (rather than the sqllineClient) from the bin subdirectory of your Amazon Kinesis Data Analytics home, which can show your results without the Amazon Kinesis Data Analytics application or JDBC:
Rules for Specifying Intervals
A DayTime Interval Literal is a string that denotes a single interval value: for example '10' SECONDS. Note it has two parts: the value (which must always be in singlequotes) and the qualifier (here, SECONDS), which give the units for the value.
The qualifier takes the following form:
DAY HOUR MINUTE SECOND [TO HOUR MINUTE SECOND]
YEAR TO MONTH intervals require a dash separating the values, whereas DAY TO HOUR intervals use a space to separate the values, as seen in the 2nd, 3rd, 5th, and 6th examples in that topic.
In addition, the leading term has to be of greater significance than the optional trailing term, so this means you can only specify:
DAY HOUR MINUTE SECOND DAY TO HOUR DAY TO MINUTE DAY TO SECOND HOUR TO MINUTE HOUR TO SECOND MINUTE TO SECOND
The easiest way to understand these may be to translate X TO Y as "Xs to the nearest Y". Hence, DAY TO HOUR is "days to the nearest hour".
When DAY, HOUR, or MINUTE is the leading term, you can specify a precision, e.g., DAY(3) TO HOUR, indicating the number of digits the associated field in the value can have. The maximum precision is 10, and the default is 2. You can't specify precision for HOUR, OR MINUTE in the trailing term  they are always of precision 2. So for example, HOUR(3) TO MINUTE is legal, HOUR TO MINUTE(3) is not.
SECOND can also take a precision, but the way it is specified differs depending on whether it is the leading or trailing field.

If SECOND is the leading field, you can specify the digits before and after the decimal point. For example, SECOND(3,3) would allow you to specify up to 999.999 seconds. The default is (2,3), which is actually a deviation from the SQL:2008 spec (it should be (2,6), but we only have millisecond precision).

If SECOND is the trailing field, you can only specify precision for the fractional seconds, that is, the part shown after the seconds' decimal point below. For example, SECOND(3) would indicate milliseconds. The default is 3 digits after the decimal point, but as above this is a deviation from the standard of 6.
As for the value, it takes the general form of:
[+]'[+]DD HH:MM:SS.SSS'
Where DD are digits indicating days, HH hours, MM minutes, and SS.SSS is seconds (adjust the number of digits appropriately if precision is explicitly specified).
Not all values have to include all fields—you can trim from both front or back, but not from in the middle. So you could make it 'DD HH' or 'MM:SS.SSS', but not 'DD MM'.
However you write it, though, the value must match the qualifier, as shown following:
INTERVAL '25 3' DAY to HOUR > legal INTERVAL '3:45:04.0' DAY TO HOUR > illegal
As stated in the SQL spec, if the precision is not explicitly specified, it is implied to be 2. Thus:

INTERVAL '120' MINUTE is an illegal interval. The legal form for the desired interval is INTERVAL '120' MINUTE(2)
and

INTERVAL '120' SECOND is not legal. The legal form for the desired interval is INTERVAL '120' SECOND(3).
values INTERVAL '120' MINUTE(2); Error: From line 1, column 8 to line 1, column 31: Interval field value 120 exceeds precision of MINUTE(2) field values INTERVAL '120' MINUTE(3); Conversion not supported
Also, if HOUR, MINUTE, or SECOND are not the leading field, they must fall in the following ranges (taken from Table 6 in topic 4.6.3 of the SQL:2008 foundation spec), as shown following:
HOUR: 023 MINUTE: 059 SECOND: 059.999
Yearmonth intervals are similar, except that the qualifiers are as shown following:
YEAR MONTH YEAR TO MONTH
Precision can be specified just as with DAY and HOUR, and the max of 10 and default of 2 is the same.
The value format for yearmonth is: 'YYMM'. If MONTH is the trailing field, it must fall in the range 011.
<interval qualifier> := <start field> TO <end field> <single datetime field> <start field> := <nonsecond primary datetime field> [ <left paren> <interval leading field precision> <right paren> ] <end field> := <nonsecond primary datetime field> SECOND [ <left paren> <interval fractional seconds precision> <right paren> ] <single datetime field> := <nonsecond primary datetime field> [ <left paren> <interval leading field precision> <right paren> ] SECOND [ <left paren> <interval leading field precision> [ <comma> <interval fractional seconds precision> ] <right paren> ] <primary datetime field> := <nonsecond primary datetime field> SECOND <nonsecond primary datetime field> := YEAR MONTH DAY HOUR MINUTE <interval fractional seconds precision> := <unsigned integer> <interval leading field precision> := <unsigned integer>