plist StartCalendar date and time syntax

I have a plist I am using to kick off a job every half hour, but I would
like to restrict it to, for example only every half hour from 8:15 to
17:45.

I have come up with this, but I wonder if there's a more elegant way.

<key>StartCalendarInterval</key>
<array>
<dict>
<key>Hour</key>
<integer>08</integer>
<key>Minute</key>
<integer>15</integer>
</dict>
<dict>
<key>Hour</key>
<integer>08</integer>
<key>Minute</key>
<integer>45</integer>
</dict>
<dict>
<key>Hour</key>
<integer>09</integer>
<key>Minute</key>
<integer>15</integer>
</dict>

.... etc
</array>

According to the man page for launchd.plist(5) under
StartCalendarInterval:

"The semantics are much like crontab(5)."

But so far I don't seem to be able to specify lists or steps as
described by man 5 crontab. Should these be specified as strings instead
or am I stuck with specifying each event in turn?

--
Paul Sture