Java HotSpot Virtual Machine

Does the date stamp represent the time a GC begins or the time it finishes?
How does the date stamp correlate to the elapsed time stamp?
I have 2 entries in a heap log with the same date stamp (2008-11-26T09:02:10.166) but different elapsed time stamps (30152.549 and 30152.565)



{Heap before GC invocations=235 (full 0):
PSYoungGen total 156544K, used 47199K [0x61920000, 0x6c550000, 0x6c550000)
eden space 137280K, 27% used [0x61920000,0x63e42ae0,0x69f30000)
from space 19264K, 47% used [0x6b280000,0x6bb75248,0x6c550000)
to space 19520K, 0% used [0x69f30000,0x69f30000,0x6b240000)
PSOldGen total 1410880K, used 1097205K [0x0b750000, 0x61920000, 0x61920000)
object space 1410880K, 77% used [0x0b750000,0x4e6cd4e0,0x61920000)
PSPermGen total 131072K, used 51731K [0x03750000, 0x0b750000, 0x0b750000)
object space 131072K, 39% used [0x03750000,0x069d4e38,0x0b750000)
2008-11-26T09:02:10.166-0700: 30152.549: [GC
Desired survivor size 21561344 bytes, new threshold 1 (max 15)
[PSYoungGen: 47199K->647K(137984K)] 1144404K->1103968K(1548864K), 0.0151170 secs] [Times: user=0.00 sys=0.00, real=0.00 secs]
Heap after GC invocations=235 (full 0):
PSYoungGen total 137984K, used 647K [0x61920000, 0x6c550000, 0x6c550000)
eden space 137280K, 0% used [0x61920000,0x61920000,0x69f30000)
from space 704K, 91% used [0x69f30000,0x69fd1d70,0x69fe0000)
to space 21056K, 0% used [0x6b0c0000,0x6b0c0000,0x6c550000)
PSOldGen total 1410880K, used 1103321K [0x0b750000, 0x61920000, 0x61920000)
object space 1410880K, 78% used [0x0b750000,0x4ecc6428,0x61920000)
PSPermGen total 131072K, used 51731K [0x03750000, 0x0b750000, 0x0b750000)
object space 131072K, 39% used [0x03750000,0x069d4e38,0x0b750000)
}
{Heap before GC invocations=236 (full 1):
PSYoungGen total 137984K, used 647K [0x61920000, 0x6c550000, 0x6c550000)
eden space 137280K, 0% used [0x61920000,0x61920000,0x69f30000)
from space 704K, 91% used [0x69f30000,0x69fd1d70,0x69fe0000)
to space 21056K, 0% used [0x6b0c0000,0x6b0c0000,0x6c550000)
PSOldGen total 1410880K, used 1103321K [0x0b750000, 0x61920000, 0x61920000)
object space 1410880K, 78% used [0x0b750000,0x4ecc6428,0x61920000)
PSPermGen total 131072K, used 51731K [0x03750000, 0x0b750000, 0x0b750000)
object space 131072K, 39% used [0x03750000,0x069d4e38,0x0b750000)
2008-11-26T09:02:10.166-0700: 30152.565: [Full GC (System) [PSYoungGen: 647K->0K(137984K)] [PSOldGen: 1103321K->819113K(1410880K)] 1103968K->819113K(1548864K) [PSPermGen: 51731K->51731K(131072K)], 3.3417616 secs] [Times: user=3.05 sys=0.03, real=3.34 secs]
Heap after GC invocations=236 (full 1):
PSYoungGen total 137984K, used 0K [0x61920000, 0x6c550000, 0x6c550000)
eden space 137280K, 0% used [0x61920000,0x61920000,0x69f30000)
from space 704K, 0% used [0x69f30000,0x69f30000,0x69fe0000)
to space 21056K, 0% used [0x6b0c0000,0x6b0c0000,0x6c550000)
PSOldGen total 1410880K, used 819113K [0x0b750000, 0x61920000, 0x61920000)
object space 1410880K, 58% used [0x0b750000,0x3d73a448,0x61920000)
PSPermGen total 131072K, used 51731K [0x03750000, 0x0b750000, 0x0b750000)
object space 131072K, 39% used [0x03750000,0x069d4e38,0x0b750000)
}




The options in use are:
-verbose:gc
-XX:+PrintGCDetails
-XX:+PrintGCDateStamps
-XX:+PrintGCDetails
-XX:+PrintHeapAtGC
-XX:+PrintTenuringDistribution

This is service pack 10 running with -server