(tz) RFE: Need public supported interface to DST timezone values.

The Solaris Management Products and Tools Group needs the following read-only daylight savings time values from the Java Time Zone APIs:

startYear
startMonth
startDay
startDayOfWeek
startTime
endMonth
endDay
EndDayOfWeek
endTime

The Solaris Management Products and Tools Group delivers the System Management Console, a Java application that launches a number of Java-based system management tools. The System Management Console, the management applications, and the underlying software must comply with the CIM (Common Information Model) specification to ensure interoperability with other vendors.

One of the Console applications, the System Information Tool, uses Java time zone APIs to get and set time zone data on a local system. The string version of the Calendar for the TimeZone object includes the following text strings that are used to display the start and end of daylight savings time for a given time zone (For a complete description of these data, see the attached CIM_TimeZone specification submitted to the Desktop Management Task Force (DMTF):

startYear - The first year in which this particular daylight
savings period became/will be effective.

startMonth - The month in which daylight savings time starts.

startDay - The day-of-week-in-month on which daylight savings
time starts.

startDayOfWeek - Positive or negative integer used in conjunction with
                  startDay to indicate the day of the week on which
                  daylight savings time starts.
                 
startTime - The time interval after midnight when daylight
savings time takes effect.

endMonth - The month in which daylight savings time ends.

endDay - The day-of-week-in-month on which daylight savings
time ends.

EndDayOfWeek - Positive or negative integer used in conjunction with
endDay to indicate the day of the week in which
daylight savings time ends.

endTime - The time interval after midnight when daylight savings
time ends.


I have checked the JDK1.4 sources and the javadocs and can find no way to access any data about the daylight savings time start and end rules. The TimeZone API needs to provide a public interface to these daylight savings time data.

The strings for these data exist in the zoneinfo object when the timezone is using daylight savings time. As a workaround, I can check if the timezone uses daylight savings time and if it does, parse the strings and get the daylight savings time rules.

My concern is that this data could change or be removed. Our group has a CIM requirement for this data and requires a public supported interface to the data in the JDK.