Index: subversion/include/svn_opt.h
===================================================================
--- subversion/include/svn_opt.h	(revision 15370)
+++ subversion/include/svn_opt.h	(working copy)
@@ -234,7 +234,8 @@
  *
  * Use @a pool for temporary allocations.
  */
-int svn_opt_parse_revision (svn_opt_revision_t *start_revision,
+svn_error_t * 
+    svn_opt_parse_revision (svn_opt_revision_t *start_revision,
                             svn_opt_revision_t *end_revision,
                             const char *arg,
                             apr_pool_t *pool);
Index: subversion/libsvn_subr/opt.c
===================================================================
--- subversion/libsvn_subr/opt.c	(revision 15370)
+++ subversion/libsvn_subr/opt.c	(working copy)
@@ -315,9 +315,13 @@
 /* Parse one revision specification.  Return pointer to character
    after revision, or NULL if the revision is invalid.  Modifies
    str, so make sure to pass a copy of anything precious.  Uses
-   POOL for temporary allocation. */
+   POOL for temporary allocation. 
+
+   @a ret_error allows us to pass up error data without needing to 
+   completely refactor the rest of this function.
+*/
 static char *parse_one_rev (svn_opt_revision_t *revision, char *str,
-                            apr_pool_t *pool)
+                            apr_pool_t *pool, svn_error_t **err)
 {
   char *end, save;
 
@@ -325,7 +329,6 @@
     {
       svn_boolean_t matched;
       apr_time_t tm;
-      svn_error_t *err;
 
       /* Brackets denote a date. */
       str++;
@@ -333,12 +336,9 @@
       if (!end)
         return NULL;
       *end = '\0';
-      err = svn_parse_date (&matched, &tm, str, apr_time_now (), pool);
-      if (err)
-        {
-          svn_error_clear (err);
+      *err = svn_parse_date (&matched, &tm, str, apr_time_now (), pool);
+      if (*err)
           return NULL;
-        }
       if (!matched)
         return NULL; 
       revision->kind = svn_opt_revision_date;
@@ -355,7 +355,7 @@
       *end = '\0';
       revision->kind = svn_opt_revision_number;
       revision->value.number = SVN_STR_TO_REV (str);
-      *end = save;
+      *end = save; 
       return end;
     }
   else if (apr_isalpha (*str))
@@ -371,33 +371,38 @@
       return end;
     }
   else
-    return NULL;
+    {
+      *err = svn_error_create(SVN_ERR_INCORRECT_PARAMS,NULL,NULL);
+      return NULL;
+    }
 }
 
 
-int
+svn_error_t *
 svn_opt_parse_revision (svn_opt_revision_t *start_revision,
                         svn_opt_revision_t *end_revision,
                         const char *arg,
                         apr_pool_t *pool)
 {
   char *left_rev, *right_rev, *end;
+  svn_error_t **err;
 
   /* Operate on a copy of the argument. */
   left_rev = apr_pstrdup (pool, arg);
+  right_rev = parse_one_rev (start_revision, left_rev, pool, &err);
 
-  right_rev = parse_one_rev (start_revision, left_rev, pool);
   if (right_rev && *right_rev == ':')
     {
       right_rev++;
-      end = parse_one_rev (end_revision, right_rev, pool);
+      /* Will this overwrite of the err variable cause a problem? */
+      end = parse_one_rev (end_revision, right_rev, pool, &err);
       if (!end || *end != '\0')
-        return -1;
+         return (svn_error_t*) err;              // pass the error up
     }
   else if (!right_rev || *right_rev != '\0')
-    return -1;
+     return (svn_error_t*) err;
 
-  return 0;
+  return SVN_NO_ERROR;
 }
 
 
@@ -486,6 +491,7 @@
                     apr_pool_t *pool)
 {
   int i;
+  svn_error_t *err = '\0';
 
   /* scanning from right to left, just to be friendly to any
      screwed-up filenames that might *actually* contain @-signs.  :-) */
@@ -499,7 +505,6 @@
       if (path[i] == '@')
         {
           svn_boolean_t is_url;
-          int ret;
           svn_opt_revision_t start_revision, end_revision;
 
           end_revision.kind = svn_opt_revision_unspecified;
@@ -511,23 +516,23 @@
             {
               if (is_url)
                 {
-                  ret = svn_opt_parse_revision (&start_revision, &end_revision,
+                  err = svn_opt_parse_revision (&start_revision, &end_revision,
                                                 "head", pool);
                 }
               else
                 {
-                  ret = svn_opt_parse_revision (&start_revision, &end_revision,
+                  err = svn_opt_parse_revision (&start_revision, &end_revision,
                                                 "base", pool);
                 }
             }
           else  /* looking at non-empty peg revision */
             {
-              ret = svn_opt_parse_revision (&start_revision,
+              err = svn_opt_parse_revision (&start_revision,
                                             &end_revision,
                                             path + i + 1, pool);
             }
 
-          if (ret || end_revision.kind != svn_opt_revision_unspecified)
+          if (err || end_revision.kind != svn_opt_revision_unspecified)
             return svn_error_createf (SVN_ERR_CL_ARG_PARSING_ERROR, NULL,
                                       _("Syntax error parsing revision '%s'"),
                                       path + i + 1);
Index: subversion/libsvn_subr/date.c
===================================================================
--- subversion/libsvn_subr/date.c	(revision 15370)
+++ subversion/libsvn_subr/date.c	(working copy)
@@ -203,14 +203,22 @@
   if (apr_err != APR_SUCCESS)
     return svn_error_wrap_apr (apr_err, _("Can't manipulate current date"));
 
+  /* The ISO-8601 standard forces the date to be a fully zero padded string
+   * to aid in the _sorting_ of dates.  We are conditioning user input
+   * instead of sorting therefore allow a relaxation of the standard for 
+   * months, days and hours which use a seperator to omit leading zeros.
+   *
+   * But _not_ entire fields.     eg) 2005-7-7T9:00Z
+   */
+
   if (template_match (&expt, &localtz, /* ISO-8601 extended, date only */
-                      "YYYY-MM-DD",
+                      "YYYY-M[M]-D[D]",
                       text)
       || template_match (&expt, &localtz, /* ISO-8601 extended, UTC */
-                      "YYYY-MM-DDThh:mm[:ss[.u[u[u[u[u[u][Z]",
+                      "YYYY-M[M]-D[D]Th[h]:mm[:ss[.u[u[u[u[u[u][Z]",
                       text)
       || template_match (&expt, &localtz, /* ISO-8601 extended, with offset */
-                         "YYYY-MM-DDThh:mm[:ss[.u[u[u[u[u[u]+OO[:oo]",
+                         "YYYY-M[M]-D[D]Th[h]:mm[:ss[.u[u[u[u[u[u]+OO[:oo]",
                          text)
       || template_match (&expt, &localtz, /* ISO-8601 basic, date only */
                          "YYYYMMDD",
@@ -222,17 +230,17 @@
                          "YYYYMMDDThhmm[ss[.u[u[u[u[u[u]+OO[oo]",
                          text)
       || template_match (&expt, &localtz, /* "svn log" format */
-                         "YYYY-MM-DD hh:mm[:ss[.u[u[u[u[u[u][ +OO[oo]",
+                         "YYYY-M[M]-D[D] h[h]:mm[:ss[.u[u[u[u[u[u][ +OO[oo]",
                          text)
       || template_match (&expt, &localtz, /* GNU date's iso-8601 */
-                         "YYYY-MM-DDThh:mm[:ss[.u[u[u[u[u[u]+OO[oo]",
+                         "YYYY-M[M]-D[D]Th[h]:mm[:ss[.u[u[u[u[u[u]+OO[oo]",
                          text))
     {
       expt.tm_year -= 1900;
       expt.tm_mon -= 1;
     }
   else if (template_match (&expt, &localtz, /* Just a time */
-                           "hh:mm[:ss[.u[u[u[u[u[u]",
+                           "h[h]:mm[:ss[.u[u[u[u[u[u]",
                            text))
     {
       expt.tm_year = expnow.tm_year;
@@ -240,10 +248,13 @@
       expt.tm_mday = expnow.tm_mday;
     }
   else
-    return SVN_NO_ERROR;
+    // This error message is overridden by the one in the client.
+    return svn_error_createf (SVN_ERR_BAD_DATE, NULL, 
+                              "Date not in ISO-8601 or GNU format");
 
   /* Range validation, allowing for leap seconds */
   if (expt.tm_mon < 0 || expt.tm_mon > 11
+      || expt.tm_mday < 1
       || expt.tm_mday > valid_days_by_month[expt.tm_mon]
       || expt.tm_hour > 23
       || expt.tm_min > 59
Index: subversion/clients/cmdline/main.c
===================================================================
--- subversion/clients/cmdline/main.c	(revision 15370)
+++ subversion/clients/cmdline/main.c	(working copy)
@@ -803,7 +803,7 @@
 int
 main (int argc, const char * const *argv)
 {
-  svn_error_t *err;
+  svn_error_t *err, *str_err;
   apr_allocator_t *allocator;
   apr_pool_t *pool;
   int opt_id;
@@ -910,17 +910,30 @@
                  "try '-r M:N' instead of '-r M -r N'"));
             return svn_cmdline_handle_exit_error (err, pool, "svn: ");
           }
-        if (svn_opt_parse_revision (&(opt_state.start_revision),
-                                    &(opt_state.end_revision),
-                                    opt_arg, pool) != 0)
+        // We execute the function/procedure and check the return value.
+        err = svn_opt_parse_revision (&(opt_state.start_revision),
+                                      &(opt_state.end_revision),
+                                      opt_arg, pool);
+        if (err != SVN_NO_ERROR)
           {
-            err = svn_utf_cstring_to_utf8 (&utf8_opt_arg, opt_arg, pool);
-            if (! err)
-              err = svn_error_createf
-                (SVN_ERR_CL_ARG_PARSING_ERROR, NULL,
-                 _("Syntax error in revision argument '%s'"),
-                 utf8_opt_arg);
-            return svn_cmdline_handle_exit_error (err, pool, "svn: ");
+            str_err = svn_utf_cstring_to_utf8 (&utf8_opt_arg, opt_arg, pool);
+            if (! str_err )
+            switch (err->apr_err)
+              {
+                case SVN_ERR_BAD_DATE: 
+                         err = svn_error_createf
+                               (SVN_ERR_BAD_DATE, NULL,
+                               _("'%s' is not in ISO-8061 or GNU format"),
+                               utf8_opt_arg);
+                         break;
+                default:
+                         err = svn_error_createf
+                               (SVN_ERR_CL_ARG_PARSING_ERROR, NULL,
+                               _("Syntax error in revision argument '%s'"),
+                               utf8_opt_arg);
+              }
+            if (str_err == SVN_NO_ERROR)
+                return svn_cmdline_handle_exit_error (err, pool, "svn: ");
           }
         break;
       case 'v':
Index: subversion/tests/libsvn_subr/time-test.c
===================================================================
--- subversion/tests/libsvn_subr/time-test.c	(revision 15370)
+++ subversion/tests/libsvn_subr/time-test.c	(working copy)
@@ -203,6 +203,8 @@
 static struct date_test localtz_tests[] = {
   /* YYYY-MM-DD */
   { "2013-01-25",                      2013,  1, 25,  0,  0,  0,      0 },
+  { "2013-1-25",                       2013,  1, 25,  0,  0,  0,      0 },
+  { "2013-01-2",                       2013,  1,  2,  0,  0,  0,      0 },
   /* YYYY-MM-DD[Thh:mm[:ss[.u[u[u[u[u[u] */
   { "2015-04-26T00:01:59.652655",      2015,  4, 26,  0,  1, 59, 652655 },
   { "2034-07-20T17:03:36.11379",       2034,  7, 20, 17,  3, 36, 113790 },
@@ -263,6 +265,7 @@
   "2000-00-02",           /* Invalid month */
   "2000-13-02",           /* Invalid month */
   "2000-01-32",           /* Invalid day */
+  "2000-01-00",
   "1999-02-29",           /* Invalid leap day */
   "2000-01-01 24:00:00",  /* Invalid hour */
   "2000-01-01 00:60:00",  /* Invalid minute */