Fixed edge case involving date time string with seconds.

When supplying a date time string with seconds (11/5/2013 11:45:00), the resulting DateTime object would not round the fractional seconds resulting in a time string of 11/5/2013 11:44:59. 

Time is now properly rounded before returning the DateTime object.

lib/roo/excelx.rb

@@ -140,10 +140,7 @@ def cell(row, col, sheet=nil)
       yyyy,mm,dd = @cell[sheet][[row,col]].split('-')
       return Date.new(yyyy.to_i,mm.to_i,dd.to_i)
     elsif celltype(row,col,sheet) == :datetime
-      date_part,time_part = @cell[sheet][[row,col]].split(' ')
-      yyyy,mm,dd = date_part.split('-')
-      hh,mi,ss = time_part.split(':')
-      return DateTime.civil(yyyy.to_i,mm.to_i,dd.to_i,hh.to_i,mi.to_i,ss.to_i)
+      return create_datetime_from( @cell[sheet][[row,col]] )
     end
     @cell[sheet][[row,col]]
   end
@@ -367,7 +364,7 @@ def set_cell_values(sheet,x,y,i,v,value_type,formula,
       when :date
         (base_date+v.to_i).strftime("%Y-%m-%d")
       when :datetime
-        (base_date+v.to_f.round(6)).strftime("%Y-%m-%d %H:%M:%S")
+        (base_date+v.to_f.round(6)).strftime("%Y-%m-%d %H:%M:%S.%N")
       when :percentage
         v.to_f
       when :time
@@ -671,4 +668,17 @@ def read_base_date
     base_date
   end
 
+  def create_datetime_from(datetime_string)
+    date_part,time_part = round_time_from(datetime_string).split(' ')
+    yyyy,mm,dd = date_part.split('-')
+    hh,mi,ss = time_part.split(':')
+    return DateTime.civil(yyyy.to_i,mm.to_i,dd.to_i,hh.to_i,mi.to_i,ss.to_i)
+  end
+
+  def round_time_from(datetime_string)
+    date_part,time_part = datetime_string.split(' ')
+    yyyy,mm,dd = date_part.split('-')
+    hh,mi,ss = time_part.split(':')
+    Time.new(yyyy.to_i, mm.to_i, dd.to_i, hh.to_i, mi.to_i, ss.to_r).round(0).strftime("%Y-%m-%d %H:%M:%S")
+  end
 end # class

test/files/datetime.xml

@@ -69,6 +69,11 @@
     <Cell ss:StyleID="s21"><Data ss:Type="DateTime">1961-11-21T00:00:00.000</Data></Cell>
     <Cell ss:StyleID="s21"><Data ss:Type="DateTime">1961-11-21T00:00:00.000</Data></Cell>
    </Row>
+   <Row>
+    <Cell ss:StyleID="s20"><Data ss:Type="DateTime">2013-11-05T11:45:00.000</Data></Cell>
+    <Cell ss:StyleID="s20"><Data ss:Type="DateTime">2013-11-05T11:45:00.000</Data></Cell>
+    <Cell ss:StyleID="s20"><Data ss:Type="DateTime">2013-11-05T11:45:00.000</Data></Cell>
+   </Row>
   </Table>
   <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
    <PageSetup>

test/test_roo.rb

@@ -1413,6 +1413,9 @@ def test_datetime
       assert_equal Date.new(1961,11,21), oo.cell('a',7)
       assert_equal Date.new(1961,11,21), oo.cell('b',7)
       assert_equal Date.new(1961,11,21), oo.cell('c',7)
+      assert_equal DateTime.new(2013,11,5,11,45,00), oo.cell('a',8)
+      assert_equal DateTime.new(2013,11,5,11,45,00), oo.cell('b',8)
+      assert_equal DateTime.new(2013,11,5,11,45,00), oo.cell('c',8)
     end
   end