I'm seing quite an odd thing (read: maybe a bug) with the
modification-dates returned from ZipEntry.
This may be an old bug fixed in a gcj version newer than my 3.4.3.
Nevertheless, I have the simple source given below that just enumerates
each entry in a zip file and prints out the modification date.
I tried testing this with a simple WinZip archive and a JAR
(both containing the same file) and the current mainline.
Both JDK 1.5.0.03 and GCJ produce the same timestamp for
both the archives, except that GCJ chooses to call my
timezone "GMT+5:30" while the JDK calls it "IST".
Hope this helps,