diff --git a/components/fpspreadsheet/examples/opendocdemo/opendocwrite.lpr b/components/fpspreadsheet/examples/opendocdemo/opendocwrite.lpr
index 19a0fb20d..9769918ce 100644
--- a/components/fpspreadsheet/examples/opendocdemo/opendocwrite.lpr
+++ b/components/fpspreadsheet/examples/opendocdemo/opendocwrite.lpr
@@ -19,6 +19,7 @@ var
   MyDir: string;
   number1, number2, number3, number4,
   number5, number6, number7, number8: Double;
+  dt1, dt2: TDateTime;
   row: Integer = 7;
 begin
   MyDir := ExtractFilePath(ParamStr(0));
@@ -31,6 +32,9 @@ begin
   number7 := 1/number3;
   number8 := -1/number3;
 
+  dt1 := EncodeDate(2012, 1, 1) + EncodeTime(9, 1, 2, 12);
+  dt2 := EncodeDate(2012, 12, 1) + EncodeTime(21, 1, 2, 12);
+
   // Create the spreadsheet
   MyWorkbook := TsWorkbook.Create;
   MyWorksheet := MyWorkbook.AddWorksheet('My Worksheet');
@@ -230,6 +234,65 @@ begin
   MyWorksheet.WriteCurrency(row, 6, number6, nfAccountingRed, 2, 'EUR', pcfCSV, ncfMCSV);
   MyWorksheet.WriteCurrency(row, 7, number7, nfAccountingRed, 2, 'EUR', pcfCSV, ncfMCSV);
   MyWorksheet.WriteCurrency(row, 8, number8, nfAccountingRed, 2, 'EUR', pcfCSV, ncfMCSV);
+  inc(row,2);
+  MyWorksheet.WriteUTF8Text(row, 0, 'Some date/time values in various formats:');
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfShortDateTime');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfShortDateTime);
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfShortDateTime);
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfShortDate');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfShortDate);
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfShortDate);
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfLongDate');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfLongDate);
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfLongDate);
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfShortTime');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfShortTime);
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfShortTime);
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfLongTime');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfLongTime);
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfLongTime);
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfShortTimeAM');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfShortTimeAM);
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfShortTimeAM);
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfLongTimeAM');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfLongTimeAM);
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfLongTimeAM);
+  inc(row);
+  // In order to use a semicolon as a date-time separator it must be escaped either by
+  // using the backslash or quotes (because the semicolon is the separator between sections)
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfCustom, dddd, dd/mm/yyyy\; hh:nn');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfCustom, 'dddd, dd/mm/yyyy\; hh:nn');
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfCustom, 'dddd, dd/mm/yyyy\; hh:nn');
+  MyWorksheet.WriteUTF8Text(row, 3, 'The semicolon must be escaped otherwise it would be misunderstood as a section separator.');
+  MyWorksheet.WriteUTF8Text(row, 4, 'This format is not displayed correctly by Open/LibreOffice.');
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfCustom, dddd, dd/mm/yyyy"; "hh:nn');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfCustom, 'dddd, dd/mm/yyyy"; "hh:nn');
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfCustom, 'dddd, dd/mm/yyyy"; "hh:nn');
+  MyWorksheet.WriteUTF8Text(row, 3, 'The semicolon must be escaped otherwise it would be misunderstood as a section separator.');
+  MyWorksheet.WriteUTF8Text(row, 4, 'This format is not displayed correctly by Open/LibreOffice.');
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfCustom, dd/mmm');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfCustom, 'dd/mmm');
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfCustom, 'dd/mmm');
+  MyWorksheet.WriteUTF8Text(row, 3, 'The slash is replaced by the date or time separator of the FormatSettings');
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfCustom, mmm/yy');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfCustom, 'mmm/yy');
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfCustom, 'mmm/yy');
+  MyWorksheet.WriteUTF8Text(row, 3, 'The slash is replaced by the date or time separator of the FormatSettings');
+  inc(row);
+  MyWorksheet.WriteUTF8Text(row, 0, 'nfCustom, mmm-yy');
+  MyWorksheet.WriteDateTime(row, 1, dt1, nfCustom, 'mmm-yy');
+  MyWorksheet.WriteDateTime(row, 2, dt2, nfCustom, 'mmm-yy');
+  MyWorksheet.WriteUTF8Text(row, 3, 'The dash is used literally');
 
   // Creates a new worksheet
   MyWorksheet := MyWorkbook.AddWorksheet('My Worksheet 2');
diff --git a/components/fpspreadsheet/fpsnumformatparser.pas b/components/fpspreadsheet/fpsnumformatparser.pas
index f2b15c74d..2abfc46e9 100644
--- a/components/fpspreadsheet/fpsnumformatparser.pas
+++ b/components/fpspreadsheet/fpsnumformatparser.pas
@@ -275,12 +275,16 @@ function TsNumFormatParser.AnalyzeCurrency(const AValue: String): Boolean;
 var
   uValue: String;
 begin
-  uValue := Uppercase(AValue);
-  Result := (uValue = Uppercase(AnsiToUTF8(FWorkbook.FormatSettings.CurrencyString))) or
-            (uValue = '$') or (uValue = 'USD') or
-            (uValue = '€') or (uValue = 'EUR') or
-            (uValue = '£') or (uValue = 'GBP') or
-            (uValue = '¥') or (uValue = 'JPY');
+  if (FWorkbook = nil) or (FWorkbook.FormatSettings.CurrencyString = '') then
+    Result := false
+  else begin
+    uValue := Uppercase(AValue);
+    Result := (uValue = Uppercase(AnsiToUTF8(FWorkbook.FormatSettings.CurrencyString))) or
+              (uValue = '$') or (uValue = 'USD') or
+              (uValue = '€') or (uValue = 'EUR') or
+              (uValue = '£') or (uValue = 'GBP') or
+              (uValue = '¥') or (uValue = 'JPY');
+  end;
 end;
 
 { Creates a formatstring for all sections.
@@ -1528,6 +1532,11 @@ begin
         end;
       'A', 'a':
         ScanAMPM;
+      ',', '-':
+        begin
+          Addelement(nftText, FToken);
+          FToken := NextToken;
+        end
       else
         // char pointer must be at end of date/time mask.
         FToken := PrevToken;
diff --git a/components/fpspreadsheet/fpsopendocument.pas b/components/fpspreadsheet/fpsopendocument.pas
index 97bb0316a..bb87baf3c 100755
--- a/components/fpspreadsheet/fpsopendocument.pas
+++ b/components/fpspreadsheet/fpsopendocument.pas
@@ -343,9 +343,9 @@ begin
             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"';
+              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;
@@ -357,11 +357,9 @@ begin
             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"';
+              2: s := 'day number:style="long" ';
+              3: s := 'day-of-week ';
+              4: s := 'day-of-week number:style="long" ';
             end;
             Result := Result + AIndent +
               '  <number:' + s + '/>' + LineEnding;
@@ -1581,57 +1579,47 @@ procedure TsSpreadOpenDocReader.ReadNumFormats(AStylesNode: TDOMNode);
       end else
       if nodeName = 'number:year' then begin
         s := GetAttrValue(node, 'number:style');
-        if s = 'long' then fmt := fmt + 'yyyy'
-        else if s = '' then fmt := fmt + 'yy';
+        fmt := fmt + IfThen(s = 'long', 'yyyy', 'yy');
       end else
       if nodeName = 'number:month' then begin
         s := GetAttrValue(node, 'number:style');
         stxt := GetAttrValue(node, 'number:textual');
-        if (stxt = 'true') then begin // Month as text
-          if (s = 'long') then fmt := fmt + 'mmmm' else fmt := fmt + 'mmm';
-        end else begin   // Month as number
-          if (s = 'long') then fmt := fmt + 'mm' else fmt := fmt + 'm';
-        end;
+        if (stxt = 'true') then  // Month as text
+          fmt := fmt + IfThen(s = 'long', 'mmmm', 'mmm')
+        else                     // Month as number
+          fmt := fmt + IfThen(s = 'long', 'mm', 'm');
       end else
       if nodeName = 'number:day' then begin
         s := GetAttrValue(node, 'number:style');
-        stxt := GetAttrValue(node, 'number:textual');
-        if (stxt = 'true') then begin   // day as text
-          if (s = 'long') then fmt := fmt + 'dddd' else fmt := fmt + 'ddd';
-        end else begin   // day as number
-          if (s = 'long') then fmt := fmt + 'dd' else fmt := fmt + 'd';
-        end;
-      end;
+        fmt := fmt + IfThen(s = 'long', 'dd', 'd');
+      end else
       if nodeName = 'number:day-of-week' then begin
-        s := GetAttrValue(node, 'number:stye');
-        if (s = 'long') then fmt := fmt + 'dddddd' else fmt := fmt + 'ddddd';
+        s := GetAttrValue(node, 'number:style');
+        fmt := fmt + IfThen(s = 'long', 'dddd', 'ddd');
       end else
       if nodeName = 'number:hours' then begin
         s := GetAttrValue(node, 'number:style');
-        if (sovr = 'false') then begin
-          if (s = 'long') then fmt := fmt + '[hh]' else fmt := fmt + '[h]';
-        end else begin
-          if (s = 'long') then fmt := fmt + 'hh' else fmt := fmt + 'h';
-        end;
+        if (sovr = 'false') then
+          fmt := fmt + IfThen(s = 'long', '[hh]', '[h]')
+        else
+          fmt := fmt + IfThen(s = 'long', 'hh', 'h');
         sovr := '';
       end else
       if nodeName = 'number:minutes' then begin
         s := GetAttrValue(node, 'number:style');
-        if (sovr = 'false') then begin
-          if (s = 'long') then fmt := fmt + '[nn]' else fmt := fmt + '[n]';
-        end else begin
-          if (s = 'long') then fmt := fmt + 'nn' else fmt := fmt + 'n';
-        end;
+        if (sovr = 'false') then
+          fmt := fmt + IfThen(s = 'long', '[nn]', '[n]')
+        else
+          fmt := fmt + IfThen(s = 'long', 'nn', 'n');
         sovr := '';
       end else
       if nodeName = 'number:seconds' then begin
         s := GetAttrValue(node, 'number:style');
-        if (sovr = 'false') then begin
-          if (s = 'long') then fmt := fmt + '[ss]' else fmt := fmt + '[s]';
-        end else begin
-          if (s = 'long') then fmt := fmt + 'ss' else fmt := fmt + 's';
-          sovr := '';
-        end;
+        if (sovr = 'false') then
+          fmt := fmt + IfThen(s = 'long', '[ss]', '[s]')
+        else
+          fmt := fmt + IfThen(s = 'long', 'ss', 's');
+        sovr := '';
         s := GetAttrValue(node, 'number:decimal-places');
         if (s <> '') and (s <> '0') then
           fmt := fmt + '.' + DupeString('0', StrToInt(s));
@@ -1641,8 +1629,14 @@ procedure TsSpreadOpenDocReader.ReadNumFormats(AStylesNode: TDOMNode);
       else
       if nodeName = 'number:text' then begin
         childnode := node.FirstChild;
-        if childnode <> nil then
-          fmt := fmt + childnode.NodeValue;
+        if childnode <> nil then begin
+          s := childNode.NodeValue;
+          if pos(';', s) > 0 then
+            fmt := fmt + '"' + s + '"'
+            // avoid "misunderstanding" the semicolon as a section separator!
+          else
+            fmt := fmt + childnode.NodeValue;
+        end;
       end;
       node := node.NextSibling;
     end;
diff --git a/components/fpspreadsheet/fpsutils.pas b/components/fpspreadsheet/fpsutils.pas
index d47f8c515..18e4636e3 100644
--- a/components/fpspreadsheet/fpsutils.pas
+++ b/components/fpspreadsheet/fpsutils.pas
@@ -1007,6 +1007,16 @@ end;
 
 procedure SplitFormatString(const AFormatString: String; out APositivePart,
   ANegativePart, AZeroPart: String);
+
+  procedure AddToken(AToken: Char; AWhere:Byte);
+  begin
+    case AWhere of
+      0: APositivePart := APositivePart + AToken;
+      1: ANegativePart := ANegativePart + AToken;
+      2: AZeroPart := AZeroPart + AToken;
+    end;
+  end;
+
 var
   P, PStart, PEnd: PChar;
   token: Char;
@@ -1025,24 +1035,28 @@ begin
   while P < PEnd do begin
     token := P^;
     case token of
-      '"': begin   // Skip quoted strings
+      '"': begin   // Let quoted text intact
+             AddToken(token, where);
              inc(P);
              token := P^;
              while (P < PEnd) and (token <> '"') do begin
+               AddToken(token, where);
                inc(P);
                token := P^;
              end;
+             AddToken(token, where);
            end;
       ';': begin  // Separator between parts
              inc(where);
              if where = 3 then
                exit;
-           end
-      else case where of
-             0: APositivePart := APositivePart + token;
-             1: ANegativePart := ANegativePart + token;
-             2: AZeroPart := AZeroPart + token;
            end;
+      '\': begin  // Skip "Escape" character and add next char immediately
+             inc(P);
+             token := P^;
+             AddToken(token, where);
+           end;
+      else AddToken(token, where);
     end;
     inc(P);
   end;