diff --git a/components/fpspreadsheet/fpsnumformat.pas b/components/fpspreadsheet/fpsnumformat.pas
index e773f078d..7d30b6aa2 100644
--- a/components/fpspreadsheet/fpsnumformat.pas
+++ b/components/fpspreadsheet/fpsnumformat.pas
@@ -51,6 +51,7 @@ function IsDateFormat(ANumFormat: TsNumFormatParams): Boolean;
 function IsTimeFormat(AFormat: TsNumberFormat): Boolean; overload;
 function IsTimeFormat(AFormatStr: String): Boolean; overload;
 function IsTimeFormat(ANumFormat: TsNumFormatParams): Boolean; overload;
+function IsLongTimeFormat(AFormatStr: String; ATimeSeparator: char): Boolean; overload;
 
 function IsTimeIntervalFormat(ANumFormat: TsNumFormatParams): Boolean;
 
@@ -186,6 +187,20 @@ begin
             (ANumFormat.Sections[0].Kind * [nfkTime] <> []);
 end;
 
+{@@ ----------------------------------------------------------------------------
+  Returns TRUE if the specified format string represents a long time format, i.e.
+  it contains two TimeSeparators.
+-------------------------------------------------------------------------------}
+function IsLongTimeFormat(AFormatStr: String; ATimeSeparator: Char): Boolean;
+var
+  i, n: Integer;
+begin
+  n := 0;
+  for i:=1 to Length(AFormatStr) do
+    if AFormatStr[i] = ATimeSeparator then inc(n);
+  Result := (n=2);
+end;
+
 {@@ ----------------------------------------------------------------------------
   Checks whether the specified number format parameters is a time interval
   format.
diff --git a/components/fpspreadsheet/fpspreadsheet.pas b/components/fpspreadsheet/fpspreadsheet.pas
index c04a7072b..d12d24441 100755
--- a/components/fpspreadsheet/fpspreadsheet.pas
+++ b/components/fpspreadsheet/fpspreadsheet.pas
@@ -4017,15 +4017,18 @@ begin
 
   if TryStrToDateTime(AValue, number, FWorkbook.FormatSettings) then
   begin
-    if number < 1.0 then begin    // this is a time alone
-      if not IsTimeFormat(numFmtParams) then begin
-        if SecondOf(number) = 0 then
-          WriteDateTime(ACell, number, nfShortTime)
+    if number < 1.0 then          // this is a time alone
+    begin
+      if not IsTimeFormat(numFmtParams) then
+      begin
+        if IsLongTimeFormat(AValue, FWorkbook.FormatSettings.TimeSeparator) then
+          WriteDateTime(ACell, number, nfLongTime)
         else
-          WriteDateTime(ACell, number, nfLongTime);
+          WriteDateTime(ACell, number, nfShortTime);
       end;
     end else
-    if frac(number) = 0.0 then begin  // this is a date alone
+    if frac(number) = 0.0 then  // this is a date alone
+    begin
       if not IsDateFormat(numFmtParams) then
         WriteDateTime(ACell, number, nfShortDate);
     end else