The IntervalYM methods

The following methods allow you to manipulate year-month intervals. (You can also use the Interval methods, described previously.) Some of the tasks you can perform with IntervalYM methods include the following:

Comparing two intervals:

boolean equals(Object other)
boolean greaterThan(IntervalYM other)
boolean lessThan(IntervalYM other)

Setting a value for an interval from:
- A string:
```
void fromString(String other)
void set(String string)
```
- Year and month values (large month values are converted to years):
```
void set(int years, int months)
```
- Two time stamps:
```
void set(Timestamp t1, Timestamp t2)
```

Setting the qualifier for an interval:

From the length, start code, and end code:

void setQualifier(int length, byte startcode, byte
      endcode)

Using an existing qualifier:
```
void setQualifier(short qualifier)
```

Obtaining the number of months in the interval:
```
long getMonths()
```
Creating a string representation of the interval in the format yyyy-mm:
```
String toString()
```
The fields present depend on the qualifier. Blanks replace leading zeros.