diff -r 4de15c54e59f -r c6061cadb400 mercurial/revset.py
--- a/mercurial/revset.py	Thu Feb 08 23:27:24 2018 +0530
+++ b/mercurial/revset.py	Thu Feb 15 17:18:26 2018 +0100
@@ -30,6 +30,7 @@
     smartset,
     util,
 )
+from .utils import dateutil
 
 # helpers for processing parsed tree
 getsymbol = revsetlang.getsymbol
@@ -658,7 +659,7 @@
     """
     # i18n: "date" is a keyword
     ds = getstring(x, _("date requires a string"))
-    dm = util.matchdate(ds)
+    dm = dateutil.matchdate(ds)
     return subset.filter(lambda x: dm(repo[x].date()[0]),
                          condrepr=('<date %r>', ds))