diff --git a/components/fpspreadsheet/fpsnumformatparser.pas b/components/fpspreadsheet/fpsnumformatparser.pas
index 778b382d8..f2b15c74d 100644
--- a/components/fpspreadsheet/fpsnumformatparser.pas
+++ b/components/fpspreadsheet/fpsnumformatparser.pas
@@ -147,6 +147,7 @@ type
     procedure ClearAll;
     function GetDateTimeCode(ASection: Integer): String;
     function IsDateTimeFormat: Boolean;
+    function IsTimeFormat: Boolean;
     procedure LimitDecimals;
     procedure Localize;
 
@@ -1184,6 +1185,26 @@ begin
   Result := false;
 end;
 
+{ Returns true if the format elements contain only time, no date tokens. }
+function TsNumFormatParser.IsTimeFormat: Boolean;
+var
+  section: Integer;
+  elem: Integer;
+begin
+  Result := false;
+  for section := 0 to High(FSections) do
+    for elem := 0 to High(FSections[section].Elements) do
+      if FSections[section].Elements[elem].Token in [nftHour, nftMinute, nftSecond]
+      then begin
+        Result := true;
+      end else
+      if FSections[section].Elements[elem].Token in [nftYear, nftMonth, nftDay, nftExpChar, nftCurrSymbol]
+      then begin
+        Result := false;
+        exit;
+      end;
+end;
+
 function TsNumFormatParser.IsTokenAt(AToken: TsNumFormatToken;
   ASection, AIndex: Integer): Boolean;
 begin
diff --git a/components/fpspreadsheet/fpsopendocument.pas b/components/fpspreadsheet/fpsopendocument.pas
index 3dd599760..97bb0316a 100755
--- a/components/fpspreadsheet/fpsopendocument.pas
+++ b/components/fpspreadsheet/fpsopendocument.pas
@@ -58,6 +58,9 @@ type
 
   { TsSpreadOpenDocNumFormatParser }
   TsSpreadOpenDocNumFormatParser = class(TsNumFormatParser)
+  private
+    function BuildDateTimeXMLAsString(ASection: Integer; AIndent: String;
+      out AIsTimeOnly: Boolean): String;
   protected
     function BuildXMLAsStringFromSection(ASection: Integer;
       AIndent,AFormatName: String): String;
@@ -312,6 +315,104 @@ end;
 
 { TsSpreadOpenDocNumFormatParser }
 
+function TsSpreadOpenDocNumFormatParser.BuildDateTimeXMLAsString(ASection: Integer;
+  AIndent: String; out AIsTimeOnly: boolean): String;
+var
+  el: Integer;
+  s: String;
+  prevToken: TsNumFormatToken;
+begin
+  Result := '';
+  AIsTimeOnly := true;
+  with FSections[ASection] do begin
+    el := 0;
+    while el < Length(Elements) do begin
+      case Elements[el].Token of
+        nftYear:
+          begin
+            prevToken := Elements[el].Token;
+            AIsTimeOnly := false;
+            s := IfThen(Elements[el].IntValue > 2, 'number:style="long" ', '');
+            Result := Result + AIndent +
+              '  <number:year ' + s + '/>' + LineEnding;
+          end;
+
+        nftMonth:
+          begin
+            prevToken := Elements[el].Token;
+            AIsTimeOnly := false;
+            case Elements[el].IntValue of
+              1: s := '';
+              2: s := 'number:style="long"';
+              3: s := 'number:textual="true"';
+              4: s := 'number:style="long" number:textual="true"';
+            end;
+            Result := result + AIndent +
+              '  <number:month ' + s + '/>' + LineEnding;
+          end;
+
+        nftDay:
+          begin
+            prevToken := Elements[el].Token;
+            AIsTimeOnly := false;
+            case Elements[el].IntValue of
+              1: s := 'day ';
+              2: s := 'day number:style="long"';
+              3: s := 'day number:textual="true"';
+              4: s := 'day number:style="long" number:textual="true"';
+              5: s := 'day-of-week ';
+              6: s := 'day-of-week number:style="long"';
+            end;
+            Result := Result + AIndent +
+              '  <number:' + s + '/>' + LineEnding;
+          end;
+
+        nftHour, nftMinute, nftSecond:
+          begin
+            prevToken := Elements[el].Token;
+            case Elements[el].Token of
+              nftHour  : s := 'hours ';
+              nftMinute: s := 'minutes ';
+              nftSecond: s := 'seconds ';
+            end;
+            s := s + IfThen(abs(Elements[el].IntValue) = 1, '', 'number:style="long" ');
+            if Elements[el].IntValue < 0 then
+              s := s + 'number:truncate-on-overflow="false" ';
+            Result := Result + AIndent +
+              '  <number:' + s + '/>' + LineEnding;
+          end;
+
+        nftMilliseconds:
+          begin
+             // ???
+          end;
+
+        nftDateTimeSep, nftText, nftEscaped, nftSpace:
+          begin
+            if Elements[el].TextValue = ' ' then
+              s := '<![CDATA[ ]]>'
+            else begin
+              s := Elements[el].TextValue;
+              if (s = '/') then begin
+                if prevToken in [nftYear, nftMonth, nftDay] then
+                  s := FWorkbook.FormatSettings.DateSeparator
+                else
+                  s := FWorkbook.FormatSettings.TimeSeparator;
+              end;
+            end;
+            Result := Result + AIndent +
+              '  <number:text>' + s + '</number:text>' + LineEnding;
+          end;
+
+        nftAMPM:
+          Result := Result + AIndent +
+            '  <number:am-pm />' + LineEnding;
+      end;
+      inc(el);
+    end;
+  end;
+end;
+
 function TsSpreadOpenDocNumFormatParser.BuildXMLAsString(AIndent,
   AFormatName: String): String;
 var
@@ -340,6 +441,7 @@ var
   clr: TsColorvalue;
   el: Integer;
   s: String;
+  isTimeOnly: Boolean;
 
 begin
   Result := '';
@@ -528,6 +630,23 @@ begin
             end;  // while
             Result := Result + sStyleMap + AIndent + '</number:currency-style>' + LineEnding;
           end;
+
+        // date/time
+        nftYear, nftMonth, nftDay, nftHour, nftMinute, nftSecond:
+          begin
+            s := BuildDateTimeXMLAsString(ASection, AIndent, isTimeOnly);
+            if isTimeOnly then
+              Result := Result + AIndent +
+                '<number:time-style style:name="' + AFormatName + '">' + LineEnding +
+                s + AIndent +
+                '</number:time-style>' + LineEnding
+            else
+              Result := Result + AIndent +
+                '<number:date-style style:name="' + AFormatName + '">' + LineEnding +
+                s + AIndent +
+                '</number:date-style>' + LineEnding;
+            exit;
+          end;
       end;
       inc(el);
     end;
@@ -3035,20 +3154,36 @@ end;
 *******************************************************************}
 procedure TsSpreadOpenDocWriter.WriteDateTime(AStream: TStream;
   const ARow, ACol: Cardinal; const AValue: TDateTime; ACell: PCell);
+const
+  FMT: array[boolean] of string = (ISO8601FormatExtended, ISO8601FormatTimeOnly);
+  DT: array[boolean] of string = ('date', 'time');
+  // Index "boolean" is to be understood as "isTimeOnly"
 var
-  lStyle: string = '';
+  lStyle: string;
+  strValue: String;
+  displayStr: String;
   lIndex: Integer;
+  isTimeOnly: Boolean;
 begin
   if ACell^.UsedFormattingFields <> [] then begin
     lIndex := FindFormattingInList(ACell);
-    lStyle := ' table:style-name="ce' + IntToStr(lIndex) + '" ';
+    lStyle := 'table:style-name="ce' + IntToStr(lIndex) + '" ';
   end else
     lStyle := '';
 
   // The row should already be the correct one
-  FCellContent :=
-    '  <table:table-cell office:value-type="date" office:date-value="' + FormatDateTime(ISO8601FormatExtended, AValue) + '"' + lStyle + '>' + LineEnding +
-    '  </table:table-cell>' + LineEnding;
+
+  // We have to distinguish between time-only values and values that contain date parts.
+  isTimeOnly := IsTimeFormat(ACell^.NumberFormat) or IsTimeFormat(ACell^.NumberFormatStr);
+  strValue := FormatDateTime(FMT[isTimeOnly], AValue);
+  displayStr := FormatDateTime(ACell^.NumberFormatStr, AValue);
+
+  FCellContent := Format(
+    '  <table:table-cell office:value-type="%s" office:%s-value="%s" %s>' + LineEnding +
+    '    <text:p>%s</text:p> ' + LineEnding +
+    '  </table:table-cell>' + LineEnding, [
+    DT[isTimeOnly], DT[isTimeOnly], strValue, lStyle, displayStr
+  ]);
 end;
 
 {
diff --git a/components/fpspreadsheet/fpsutils.pas b/components/fpspreadsheet/fpsutils.pas
index c17a4c592..d47f8c515 100644
--- a/components/fpspreadsheet/fpsutils.pas
+++ b/components/fpspreadsheet/fpsutils.pas
@@ -29,6 +29,8 @@ const
   ISO8601Format='yyyymmdd"T"hhmmss';
   // Extended ISO 8601 date/time format, used in e.g. ODF/opendocument
   ISO8601FormatExtended='yyyy"-"mm"-"dd"T"hh":"mm":"ss';
+  // ISO 8601 time-only format, used in ODF/opendocument
+  ISO8601FormatTimeOnly='"PT"hh"H"nn"M"ss"S"';
 
 // Endianess helper functions
 function WordToLE(AValue: Word): Word;
@@ -71,6 +73,8 @@ function IfThen(ACondition: Boolean; AValue1,AValue2: TsNumberFormat): TsNumberF
 function IsCurrencyFormat(AFormat: TsNumberFormat): Boolean;
 function IsDateTimeFormat(AFormat: TsNumberFormat): Boolean; overload;
 function IsDateTimeFormat(AFormatStr: String): Boolean; overload;
+function IsTimeFormat(AFormat: TsNumberFormat): Boolean; overload;
+function IsTimeFormat(AFormatStr: String): Boolean; overload;
 
 function BuildCurrencyFormatString(ADialect: TsNumFormatDialect;
   ANumberFormat: TsNumberFormat; const AFormatSettings: TFormatSettings;
@@ -579,6 +583,24 @@ begin
   end;
 end;
 
+function IsTimeFormat(AFormat: TsNumberFormat): boolean;
+begin
+  Result := AFormat in [nfShortTime, nfLongTime, nfShortTimeAM, nfLongTimeAM,
+    nfTimeInterval];
+end;
+
+function IsTimeFormat(AFormatStr: String): Boolean;
+var
+  parser: TsNumFormatParser;
+begin
+  parser := TsNumFormatParser.Create(nil, AFormatStr);
+  try
+    Result := parser.IsTimeFormat;
+  finally
+    parser.Free;
+  end;
+end;
+
 { Builds a date/time format string from the numberformat code. If the format code
   is nfFmtDateTime the given AFormatString is used. AFormatString can use the
   abbreviations "dm" (for "d/mmm"), "my" (for "mmm/yy"), "ms" (for "mm:ss")