diff --git a/mercurial/help/dates.txt b/mercurial/help/dates.txt
--- a/mercurial/help/dates.txt
+++ b/mercurial/help/dates.txt
@@ -30,7 +30,7 @@ the timezone is east of UTC).
 
 The log command also accepts date ranges:
 
-- ``<{datetime}`` - at or before a given date/time
-- ``>{datetime}`` - on or after a given date/time
-- ``{datetime} to {datetime}`` - a date range, inclusive
-- ``-{days}`` - within a given number of days of today
+- ``<DATE`` - at or before a given date/time
+- ``>DATE`` - on or after a given date/time
+- ``DATE to DATE`` - a date range, inclusive
+- ``-DAYS`` - within a given number of days of today
diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -1196,12 +1196,12 @@ def matchdate(date):
         raise Abort(_("dates cannot consist entirely of whitespace"))
     elif date[0] == "<":
         if not date[1:]:
-            raise Abort(_("invalid day spec. use '<{datetime}' "))
+            raise Abort(_("invalid day spec, use '<DATE'"))
         when = upper(date[1:])
         return lambda x: x <= when
     elif date[0] == ">":
         if not date[1:]:
-            raise Abort(_("invalid day spec. use '>{datetime}' "))
+            raise Abort(_("invalid day spec, use '>DATE'"))
         when = lower(date[1:])
         return lambda x: x >= when
     elif date[0] == "-":
diff --git a/tests/test-log.t b/tests/test-log.t
--- a/tests/test-log.t
+++ b/tests/test-log.t
@@ -525,13 +525,13 @@ log -d -1
 log -d ">"
 
   $ hg log -d ">"
-  abort: invalid day spec. use '>{datetime}' 
+  abort: invalid day spec, use '>DATE'
   [255]
 
 log -d "<"
 
   $ hg log -d "<"
-  abort: invalid day spec. use '<{datetime}' 
+  abort: invalid day spec, use '<DATE'
   [255]
 
 
diff --git a/tests/test-parse-date.t b/tests/test-parse-date.t
--- a/tests/test-parse-date.t
+++ b/tests/test-parse-date.t
@@ -96,31 +96,31 @@ Test 12-hours times
 Test date formats with '>' or '<' accompanied by space characters
 
   $ hg log -d '>' --template '{date|date}\n'
-  abort: invalid day spec. use '>{datetime}' 
+  abort: invalid day spec, use '>DATE'
   [255]
   $ hg log -d '<' hg log -d '>' --template '{date|date}\n'
-  abort: invalid day spec. use '>{datetime}' 
+  abort: invalid day spec, use '>DATE'
   [255]
 
   $ hg log -d ' >' --template '{date|date}\n'
-  abort: invalid day spec. use '>{datetime}' 
+  abort: invalid day spec, use '>DATE'
   [255]
   $ hg log -d ' <' --template '{date|date}\n'
-  abort: invalid day spec. use '<{datetime}' 
+  abort: invalid day spec, use '<DATE'
   [255]
 
   $ hg log -d '> ' --template '{date|date}\n'
-  abort: invalid day spec. use '>{datetime}' 
+  abort: invalid day spec, use '>DATE'
   [255]
   $ hg log -d '< ' --template '{date|date}\n'
-  abort: invalid day spec. use '<{datetime}' 
+  abort: invalid day spec, use '<DATE'
   [255]
 
   $ hg log -d ' > ' --template '{date|date}\n'
-  abort: invalid day spec. use '>{datetime}' 
+  abort: invalid day spec, use '>DATE'
   [255]
   $ hg log -d ' < ' --template '{date|date}\n'
-  abort: invalid day spec. use '<{datetime}' 
+  abort: invalid day spec, use '<DATE'
   [255]
 
   $ hg log -d '>02/01' --template '{date|date}\n'