Index: doc/clock.n
==================================================================
--- doc/clock.n
+++ doc/clock.n
@@ -911,13 +911,14 @@
 An ISO 8601 point-in-time specification, such as
 .QW \fICCyymmdd\fBT\fIhhmmss\fR,
 where \fBT\fR is the literal
 .QW T ,
 .QW "\fICCyymmdd hhmmss\fR" ,
+.QW \fICCyymmdd\fBT\fIhh:mm:ss\fR ,
 or
-.QW \fICCyymmdd\fBT\fIhh:mm:ss\fR .
-Note that only these three formats are accepted.
+.QW \fICCyy-mm-dd\fBT\fIhh:mm:ss\fR.
+Note that only these four formats are accepted.
 The command does \fInot\fR accept the full range of point-in-time
 specifications specified in ISO8601.  Other formats can be recognized by
 giving an explicit \fB\-format\fR option to the \fBclock scan\fR command.
 .TP
 \fIrelative time\fR

Index: generic/tclDate.c
==================================================================
--- generic/tclDate.c
+++ generic/tclDate.c
@@ -127,10 +127,11 @@
  * Copyright (c) 1992-1995 Karl Lehenbauer and Mark Diekhans.
  * Copyright (c) 1995-1997 Sun Microsystems, Inc.
  *
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
  */
 #include "tclInt.h"
 
 /*
  * Bison generates several labels that happen to be unused. MS Visual C++
@@ -279,11 +280,11 @@
 
 {
     time_t Number;
     enum _MERIDIAN Meridian;
 }
-/* Line 187 of yacc.c.  */
+/* Line 193 of yacc.c.  */
 
 	YYSTYPE;
 # define yystype YYSTYPE /* obsolescent; will be withdrawn */
 # define YYSTYPE_IS_DECLARED 1
 # define YYSTYPE_IS_TRIVIAL 1
@@ -532,20 +533,20 @@
 #endif
 
 /* YYFINAL -- State number of the termination state.  */
 #define YYFINAL  2
 /* YYLAST -- Last index in YYTABLE.  */
-#define YYLAST   79
+#define YYLAST   86
 
 /* YYNTOKENS -- Number of terminals.  */
 #define YYNTOKENS  26
 /* YYNNTS -- Number of nonterminals.  */
 #define YYNNTS  16
 /* YYNRULES -- Number of rules.  */
-#define YYNRULES  56
+#define YYNRULES  57
 /* YYNRULES -- Number of states.  */
-#define YYNSTATES  83
+#define YYNSTATES  89
 
 /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
 #define YYUNDEFTOK  2
 #define YYMAXUTOK   274
 
@@ -591,13 +592,13 @@
 static const yytype_uint8 yyprhs[] =
 {
        0,     0,     3,     4,     7,     9,    11,    13,    15,    17,
       19,    21,    23,    25,    28,    33,    39,    46,    54,    57,
       59,    61,    63,    66,    69,    73,    76,    80,    86,    88,
-      94,   100,   103,   108,   111,   113,   117,   120,   124,   128,
-     136,   139,   144,   147,   149,   153,   156,   159,   163,   165,
-     167,   169,   171,   173,   175,   177,   178
+      94,   100,   103,   108,   111,   113,   117,   120,   124,   136,
+     140,   148,   151,   156,   159,   161,   165,   168,   171,   175,
+     177,   179,   181,   183,   185,   187,   189,   190
 };
 
 /* YYRHS -- A `-1'-separated list of the rules' RHS.  */
 static const yytype_int8 yyrhs[] =
 {
@@ -611,27 +612,29 @@
       13,     4,    -1,    19,     4,    -1,    13,    23,    13,    -1,
       13,    23,    13,    23,    13,    -1,    17,    -1,    13,    21,
        8,    21,    13,    -1,    13,    21,    13,    21,    13,    -1,
        8,    13,    -1,     8,    13,    22,    13,    -1,    13,     8,
       -1,    15,    -1,    13,     8,    13,    -1,    19,     8,    -1,
-      19,    13,     8,    -1,    17,    14,    17,    -1,    17,    14,
-      13,    20,    13,    20,    13,    -1,    17,    17,    -1,    10,
-      13,    24,    13,    -1,    37,     3,    -1,    37,    -1,    38,
-      13,    39,    -1,    13,    39,    -1,    19,    39,    -1,    19,
-      13,    39,    -1,    39,    -1,    21,    -1,    25,    -1,    11,
-      -1,    18,    -1,     9,    -1,    13,    -1,    -1,     7,    -1
+      19,    13,     8,    -1,    13,    21,    13,    21,    13,    14,
+      13,    20,    13,    20,    13,    -1,    17,    14,    17,    -1,
+      17,    14,    13,    20,    13,    20,    13,    -1,    17,    17,
+      -1,    10,    13,    24,    13,    -1,    37,     3,    -1,    37,
+      -1,    38,    13,    39,    -1,    13,    39,    -1,    19,    39,
+      -1,    19,    13,    39,    -1,    39,    -1,    21,    -1,    25,
+      -1,    11,    -1,    18,    -1,     9,    -1,    13,    -1,    -1,
+       7,    -1
 };
 
 /* YYRLINE[YYN] -- source line where rule number YYN was defined.  */
 static const yytype_uint16 yyrline[] =
 {
-       0,   225,   225,   226,   229,   232,   235,   238,   241,   244,
-     247,   251,   256,   259,   265,   271,   279,   285,   296,   300,
-     304,   310,   314,   318,   322,   326,   332,   336,   341,   346,
-     351,   356,   360,   365,   369,   374,   381,   385,   391,   400,
-     409,   419,   433,   438,   441,   444,   447,   450,   453,   458,
-     461,   466,   470,   474,   480,   498,   501
+       0,   223,   223,   224,   227,   230,   233,   236,   239,   242,
+     245,   249,   254,   257,   263,   269,   277,   283,   294,   298,
+     302,   308,   312,   316,   320,   324,   330,   334,   339,   344,
+     349,   354,   358,   363,   367,   372,   379,   383,   389,   399,
+     408,   417,   427,   441,   446,   449,   452,   455,   458,   461,
+     466,   469,   474,   478,   482,   488,   506,   509
 };
 #endif
 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
 /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
@@ -664,39 +667,39 @@
 {
        0,    26,    27,    27,    28,    28,    28,    28,    28,    28,
       28,    28,    28,    29,    29,    29,    29,    29,    30,    30,
       30,    31,    31,    31,    31,    31,    32,    32,    32,    32,
       32,    32,    32,    32,    32,    32,    33,    33,    34,    34,
-      34,    35,    36,    36,    37,    37,    37,    37,    37,    38,
-      38,    39,    39,    39,    40,    41,    41
+      34,    34,    35,    36,    36,    37,    37,    37,    37,    37,
+      38,    38,    39,    39,    39,    40,    41,    41
 };
 
 /* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
 static const yytype_uint8 yyr2[] =
 {
        0,     2,     0,     2,     1,     1,     1,     1,     1,     1,
        1,     1,     1,     2,     4,     5,     6,     7,     2,     1,
        1,     1,     2,     2,     3,     2,     3,     5,     1,     5,
-       5,     2,     4,     2,     1,     3,     2,     3,     3,     7,
-       2,     4,     2,     1,     3,     2,     2,     3,     1,     1,
-       1,     1,     1,     1,     1,     0,     1
+       5,     2,     4,     2,     1,     3,     2,     3,    11,     3,
+       7,     2,     4,     2,     1,     3,     2,     2,     3,     1,
+       1,     1,     1,     1,     1,     1,     0,     1
 };
 
 /* YYDEFACT[STATE-NAME] -- Default rule to reduce with in state
    STATE-NUM when YYTABLE doesn't specify something else to do.  Zero
    means the default is an error.  */
 static const yytype_uint8 yydefact[] =
 {
-       2,     0,     1,    21,    20,     0,    53,     0,    51,    54,
-      19,    34,    28,    52,     0,    49,    50,     3,     4,     5,
-       8,     6,     7,    10,    11,     9,    43,     0,    48,    12,
-      22,    31,     0,    23,    13,    33,     0,     0,     0,    45,
-      18,     0,    40,    25,    36,     0,    46,    42,     0,     0,
-       0,    35,    55,     0,     0,    26,     0,    38,    37,    47,
-      24,    44,    32,    41,    56,     0,     0,    14,     0,     0,
-       0,     0,    55,    15,    29,    30,    27,     0,     0,    16,
-       0,    17,    39
+       2,     0,     1,    21,    20,     0,    54,     0,    52,    55,
+      19,    34,    28,    53,     0,    50,    51,     3,     4,     5,
+       8,     6,     7,    10,    11,     9,    44,     0,    49,    12,
+      22,    31,     0,    23,    13,    33,     0,     0,     0,    46,
+      18,     0,    41,    25,    36,     0,    47,    43,     0,     0,
+       0,    35,    56,     0,     0,    26,     0,    39,    37,    48,
+      24,    45,    32,    42,    57,     0,     0,    14,     0,     0,
+       0,     0,    56,    15,    29,    30,    27,     0,     0,    16,
+       0,     0,    17,     0,    40,     0,     0,     0,    38
 };
 
 /* YYDEFGOTO[NTERM-NUM].  */
 static const yytype_int8 yydefgoto[] =
 {
@@ -714,19 +717,19 @@
      -22,   -22,   -22,   -22,   -22,   -22,    32,    28,   -22,   -22,
      -22,    24,    26,   -22,   -22,    42,    47,    -5,    49,   -22,
      -22,    15,   -22,   -22,   -22,    48,   -22,   -22,    43,    50,
       51,   -22,    17,    44,    46,    45,    52,   -22,   -22,   -22,
      -22,   -22,   -22,   -22,   -22,    56,    57,   -22,    58,    60,
-      61,    62,    -3,   -22,   -22,   -22,   -22,    59,    63,   -22,
-      64,   -22,   -22
+      61,    62,    -3,   -22,   -22,    63,   -22,    59,    65,   -22,
+      67,    68,   -22,    64,   -22,    69,    66,    70,   -22
 };
 
 /* YYPGOTO[NTERM-NUM].  */
 static const yytype_int8 yypgoto[] =
 {
      -22,   -22,   -22,   -22,   -22,   -22,   -22,   -22,   -22,   -22,
-     -22,   -22,   -22,    -9,   -22,     6
+     -22,   -22,   -22,    -9,   -22,     4
 };
 
 /* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
    positive, shift that token.  If negative, reduce the rule which
    number is the opposite.  If zero, do what YYDEFACT says.
@@ -739,23 +742,25 @@
       13,    14,    41,    15,    64,    42,    33,    16,    56,    34,
       35,     6,    57,     8,    40,    47,    59,    65,    66,    61,
       13,    48,    36,    37,    43,    38,    49,    60,    44,     6,
       50,     8,     6,    45,     8,    51,    58,     6,    13,     8,
       52,    13,    55,    62,    63,    68,    13,    69,    70,    72,
-      73,    74,    71,    75,    76,    77,    81,    82,    79,    80
+      73,    74,    71,    75,    76,    77,    79,    80,    82,    81,
+      83,    84,    86,    88,    85,     0,    87
 };
 
-static const yytype_uint8 yycheck[] =
+static const yytype_int8 yycheck[] =
 {
        9,    22,     0,     8,     7,    14,     4,     5,    13,    13,
        8,     9,    10,    11,    13,    13,    14,    15,    21,    17,
       18,    19,    14,    21,     7,    17,     4,    25,    13,     7,
        8,     9,    17,    11,    16,     3,    45,    20,    21,    48,
       18,    13,    20,    21,     4,    23,    22,     4,     8,     9,
       24,    11,     9,    13,    11,    13,     8,     9,    18,    11,
       13,    18,    13,    13,    13,    21,    18,    21,    23,    13,
-      13,    13,    20,    13,    13,    13,    13,    13,    72,    20
+      13,    13,    20,    13,    13,    13,    72,    14,    13,    20,
+      13,    13,    13,    13,    20,    -1,    20
 };
 
 /* YYSTOS[STATE-NUM] -- The (internal number of the) accessing
    symbol of state STATE-NUM.  */
 static const yytype_uint8 yystos[] =
@@ -766,11 +771,11 @@
       22,    13,    13,     4,     7,     8,    20,    21,    23,    39,
       16,    14,    17,     4,     8,    13,    39,     3,    13,    22,
       24,    13,    13,     8,    13,    13,    13,    17,     8,    39,
        4,    39,    13,    13,     7,    20,    21,    41,    21,    21,
       23,    20,    13,    13,    13,    13,    13,    13,    21,    41,
-      20,    13,    13
+      14,    20,    13,    13,    13,    20,    13,    20,    13
 };
 
 #define yyerrok		(yyerrstatus = 0)
 #define yyclearin	(yychar = YYEMPTY)
 #define YYEMPTY		(-2)
@@ -1891,10 +1896,23 @@
 	;}
     break;
 
   case 38:
 
+    {
+	    if ((yyvsp[(6) - (11)].Number) != HOUR( 7)) YYABORT;
+	    yyYear = (yyvsp[(1) - (11)].Number);
+	    yyMonth = (yyvsp[(3) - (11)].Number);
+	    yyDay = (yyvsp[(5) - (11)].Number);
+	    yyHour = (yyvsp[(7) - (11)].Number);
+	    yyMinutes = (yyvsp[(9) - (11)].Number);
+	    yySeconds = (yyvsp[(11) - (11)].Number);
+	;}
+    break;
+
+  case 39:
+
     {
 	    if ((yyvsp[(2) - (3)].Number) != HOUR( 7)) YYABORT;
 	    yyYear = (yyvsp[(1) - (3)].Number) / 10000;
 	    yyMonth = ((yyvsp[(1) - (3)].Number) % 10000)/100;
 	    yyDay = (yyvsp[(1) - (3)].Number) % 100;
@@ -1902,11 +1920,11 @@
 	    yyMinutes = ((yyvsp[(3) - (3)].Number) % 10000)/100;
 	    yySeconds = (yyvsp[(3) - (3)].Number) % 100;
 	;}
     break;
 
-  case 39:
+  case 40:
 
     {
 	    if ((yyvsp[(2) - (7)].Number) != HOUR( 7)) YYABORT;
 	    yyYear = (yyvsp[(1) - (7)].Number) / 10000;
 	    yyMonth = ((yyvsp[(1) - (7)].Number) % 10000)/100;
@@ -1915,11 +1933,11 @@
 	    yyMinutes = (yyvsp[(5) - (7)].Number);
 	    yySeconds = (yyvsp[(7) - (7)].Number);
 	;}
     break;
 
-  case 40:
+  case 41:
 
     {
 	    yyYear = (yyvsp[(1) - (2)].Number) / 10000;
 	    yyMonth = ((yyvsp[(1) - (2)].Number) % 10000)/100;
 	    yyDay = (yyvsp[(1) - (2)].Number) % 100;
@@ -1927,11 +1945,11 @@
 	    yyMinutes = ((yyvsp[(2) - (2)].Number) % 10000)/100;
 	    yySeconds = (yyvsp[(2) - (2)].Number) % 100;
 	;}
     break;
 
-  case 41:
+  case 42:
 
     {
 	    /*
 	     * Offset computed year by -377 so that the returned years will be
 	     * in a range accessible with a 32 bit clock seconds value.
@@ -1943,93 +1961,93 @@
 	    yyRelDay += (((yyvsp[(2) - (4)].Number)%1000)*(365 + IsLeapYear(yyYear)))/1000;
 	    yyRelSeconds += (yyvsp[(4) - (4)].Number) * 144 * 60;
 	;}
     break;
 
-  case 42:
+  case 43:
 
     {
 	    yyRelSeconds *= -1;
 	    yyRelMonth *= -1;
 	    yyRelDay *= -1;
 	;}
     break;
 
-  case 44:
+  case 45:
 
     {
 	    *yyRelPointer += (yyvsp[(1) - (3)].Number) * (yyvsp[(2) - (3)].Number) * (yyvsp[(3) - (3)].Number);
 	;}
     break;
 
-  case 45:
+  case 46:
 
     {
 	    *yyRelPointer += (yyvsp[(1) - (2)].Number) * (yyvsp[(2) - (2)].Number);
 	;}
     break;
 
-  case 46:
+  case 47:
 
     {
 	    *yyRelPointer += (yyvsp[(2) - (2)].Number);
 	;}
     break;
 
-  case 47:
+  case 48:
 
     {
 	    *yyRelPointer += (yyvsp[(2) - (3)].Number) * (yyvsp[(3) - (3)].Number);
 	;}
     break;
 
-  case 48:
+  case 49:
 
     {
 	    *yyRelPointer += (yyvsp[(1) - (1)].Number);
 	;}
     break;
 
-  case 49:
+  case 50:
 
     {
 	    (yyval.Number) = -1;
 	;}
     break;
 
-  case 50:
+  case 51:
 
     {
 	    (yyval.Number) =  1;
 	;}
     break;
 
-  case 51:
+  case 52:
 
     {
 	    (yyval.Number) = (yyvsp[(1) - (1)].Number);
 	    yyRelPointer = &yyRelSeconds;
 	;}
     break;
 
-  case 52:
+  case 53:
 
     {
 	    (yyval.Number) = (yyvsp[(1) - (1)].Number);
 	    yyRelPointer = &yyRelDay;
 	;}
     break;
 
-  case 53:
+  case 54:
 
     {
 	    (yyval.Number) = (yyvsp[(1) - (1)].Number);
 	    yyRelPointer = &yyRelMonth;
 	;}
     break;
 
-  case 54:
+  case 55:
 
     {
 	    if (yyHaveTime && yyHaveDate && !yyHaveRel) {
 		yyYear = (yyvsp[(1) - (1)].Number);
 	    } else {
@@ -2045,18 +2063,18 @@
 		yyMeridian = MER24;
 	    }
 	;}
     break;
 
-  case 55:
+  case 56:
 
     {
 	    (yyval.Meridian) = MER24;
 	;}
     break;
 
-  case 56:
+  case 57:
 
     {
 	    (yyval.Meridian) = (yyvsp[(1) - (1)].Meridian);
 	;}
     break;

Index: generic/tclGetDate.y
==================================================================
--- generic/tclGetDate.y
+++ generic/tclGetDate.y
@@ -384,11 +384,21 @@
 	    yyMonthOrdinal = $2;
 	    yyMonth = $3;
 	}
 	;
 
-iso	: tISOBASE tZONE tISOBASE {
+iso	: tUNUMBER '-' tUNUMBER '-' tUNUMBER tZONE
+		tUNUMBER ':' tUNUMBER ':' tUNUMBER {
+	    if ($6 != HOUR( 7)) YYABORT;
+	    yyYear = $1;
+	    yyMonth = $3;
+	    yyDay = $5;
+	    yyHour = $7;
+	    yyMinutes = $9;
+	    yySeconds = $11;
+	}
+	| tISOBASE tZONE tISOBASE {
 	    if ($2 != HOUR( 7)) YYABORT;
 	    yyYear = $1 / 10000;
 	    yyMonth = ($1 % 10000)/100;
 	    yyDay = $1 % 100;
 	    yyHour = $3 / 10000;

Index: tests/clock.test
==================================================================
--- tests/clock.test
+++ tests/clock.test
@@ -35661,10 +35661,18 @@
     clock format $time -format {%b %d, %Y %H:%M:%S}
 } "Oct 23, 1992 23:59:59"
 test clock-34.18 {clock scan, ISO 8601 point in time format} {
     set time [clock scan "19921023T000000"]
     clock format $time -format {%b %d, %Y %H:%M:%S}
+} "Oct 23, 1992 00:00:00"
+test clock-34.19 {clock scan, ISO 8601 point in time format} {
+    set time [clock scan "19921023T00:00:00"]
+    clock format $time -format {%b %d, %Y %H:%M:%S}
+} "Oct 23, 1992 00:00:00"
+test clock-34.20 {clock scan, ISO 8601 point in time format} {
+    set time [clock scan "1992-10-23T00:00:00"]
+    clock format $time -format {%b %d, %Y %H:%M:%S}
 } "Oct 23, 1992 00:00:00"
 
 # CLOCK SCAN REAL TESTS
 # We use 5am PST, 31-12-1999 as the base for these scans because irrespective
 # of your local timezone it should always give us times on December 31, 1999

