diff --git a/hgext/convert/bzr.py b/hgext/convert/bzr.py
--- a/hgext/convert/bzr.py
+++ b/hgext/convert/bzr.py
@@ -110,8 +110,7 @@ class bzr_source(converter_source):
             self._parentids[version] = parents
 
         return commit(parents=parents,
-                # bzr uses 1 second timezone precision
-                date='%d %d' % (rev.timestamp, rev.timezone / 3600),
+                date='%d %d' % (rev.timestamp, -rev.timezone),
                 author=self.recode(rev.committer),
                 # bzr returns bytestrings or unicode, depending on the content
                 desc=self.recode(rev.message),
diff --git a/tests/test-convert-bzr b/tests/test-convert-bzr
--- a/tests/test-convert-bzr
+++ b/tests/test-convert-bzr
@@ -33,6 +33,26 @@ exclude a
 EOF
 hg convert --filemap filemap source source-filemap-hg
 hg -R source-filemap-hg manifest -r tip
+
+# extract timestamps that look just like hg's {date|isodate}:
+# yyyy-mm-dd HH:MM zzzz (no seconds!)
+echo "% compare timestamps"
+cd source
+bzr log | \
+  awk -F'[ :]' '$1 == "timestamp" { printf "%s %s:%s %s\n", $4, $5, $6, $8 }' \
+  > ../bzr-timestamps
+cd ..
+
+hg -R source-hg log --template "{date|isodate}\n" > hg-timestamps
+if diff -q bzr-timestamps hg-timestamps ; then
+  echo "good: hg timestamps match bzr timestamps"
+else
+  echo "fail: bzr timestamps are:"
+  cat bzr-timestamps
+  echo "but hg timestamps are:"
+  cat hg-timestamps
+fi
+
 cd ..
 
 echo % merge
diff --git a/tests/test-convert-bzr.out b/tests/test-convert-bzr.out
--- a/tests/test-convert-bzr.out
+++ b/tests/test-convert-bzr.out
@@ -35,6 +35,8 @@ 0 rename a into b, create a, rename c in
 b
 d
 f
+% compare timestamps
+good: hg timestamps match bzr timestamps
 % merge
 initializing destination source-hg repository
 scanning source...