presto-main/src/main/java/io/prestosql/type/TimestampOperators.java/TimestampOperators/subtract
class TimestampOperators:    @ScalarOperator(SUBTRACT)
    @SqlType(StandardTypes.INTERVAL_DAY_TO_SECOND)
    public static long subtract(@SqlType(StandardTypes.TIMESTAMP) long left, @SqlType(StandardTypes.TIMESTAMP) long right)
    {
        return left - right;
    }