diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -2044,7 +2044,7 @@ def log(ui, repo, *pats, **opts):
             if only_branches and ctx.branch() not in only_branches:
                 continue
 
-            if df and not df(ctx.date()):
+            if df and not df(ctx.date()[0]):
                 continue
 
             if opts.get('keyword'):
diff --git a/tests/test-log b/tests/test-log
--- a/tests/test-log
+++ b/tests/test-log
@@ -107,6 +107,9 @@ hg log -r 100000000000000000000000000000
 echo '% log -k r1'
 hg log -k r1
 
+echo '% log -d -1'
+hg log -d -1
+
 cd ..
 
 hg init usertest
diff --git a/tests/test-log.out b/tests/test-log.out
--- a/tests/test-log.out
+++ b/tests/test-log.out
@@ -245,6 +245,7 @@ user:        test
 date:        Thu Jan 01 00:00:01 1970 +0000
 summary:     r1
 
+% log -d -1
 adding a
 adding b
 changeset:   0:29a4c94f1924