After packing/unpacking an archive using pack.modification.time=latest
the resulting archive contains 2 modification times.

archive used:
/net/sqesvr-nfs.sfbay/global/nfs/deployment2/karim/deployment_tiger_int_tmp/data/Pack/golden.jar

For this test the File version of pack/unpack API was used.

excerpt of original archive:
  47216 10-09-03 15:17 Parser.class
      0 10-09-03 15:24 subdir3/
      0 10-09-03 15:24 subdir3/subsubdir/
      0 10-09-03 15:24 subdir3/subsubdir/subsubsubdir/
  65732 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteCp1383.class
 128118 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteCp933.class
  69610 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteCp942.class
 125345 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteCp949.class
  85521 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteEUC_KR.class
 126896 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteEUC_TW.class
  81453 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteHKSCS.class
  66265 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteMS932DB.class
  85103 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteMS950.class
 122426 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteX11GB18030_1.class
  94356 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharToByteX11Johab.class
  26186 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharacterData00.class
   4906 10-09-03 15:17 subdir3/subsubdir/subsubsubdir/CharacterDataLatin1.class
   8386 10-09-03 15:17 IdentityHashMap.class
  12941 10-09-03 15:17 String.class
      0 10-09-03 15:24 subdir4/
  20933 10-09-03 15:17 Token.class
  11401 10-09-03 15:17 ParserForXMLSchema.class
  11672 10-09-03 15:17 Converter_ko.class

excerpt of the packed/unpacked archive:
  47216 10-09-03 15:29 Parser.class
      0 10-09-03 15:29 subdir3/
      0 10-09-03 15:29 subdir3/subsubdir/
      0 10-09-03 15:29 subdir3/subsubdir/subsubsubdir/
  65732 10-09-03 15:29 subdir3/subsubdir/subsubsubdir/CharToByteCp1383.class
 128118 10-09-03 15:29 subdir3/subsubdir/subsubsubdir/CharToByteCp933.class
  69610 10-09-03 15:29 subdir3/subsubdir/subsubsubdir/CharToByteCp942.class
 125345 10-09-03 15:29 subdir3/subsubdir/subsubsubdir/CharToByteCp949.class
  85521 10-09-03 15:29 subdir3/subsubdir/subsubsubdir/CharToByteEUC_KR.class
 126896 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharToByteEUC_TW.class
  81453 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharToByteHKSCS.class
  66265 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharToByteMS932DB.class
  85103 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharToByteMS950.class
 122426 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharToByteX11GB18030_1.class
  94356 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharToByteX11Johab.class
  26186 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharacterData00.class
   4906 08-04-03 12:26 subdir3/subsubdir/subsubsubdir/CharacterDataLatin1.class
   8386 08-04-03 12:26 IdentityHashMap.class
  12941 08-04-03 12:26 String.class
      0 08-04-03 12:26 subdir4/
  20933 08-04-03 12:26 Token.class
  11401 08-04-03 12:26 ParserForXMLSchema.class
  11672 Converter_ko.class

The "08-04-03 12:26" time does not appear at all in the original jar.