Probable bug on Excel 2010

Question

It's more of a heads up for you guys since I didn't find anything about it on the internet. 
Edited to explain a bit better:  I posted this after noticing that in some situations some cells from Excel when converted for C# (using FromOADate) will seemingly lose one second, a cell with the date "10/19/2014 12:15 PM" would turn into
"10/19/2014 12:14:59 PM" inside a C# application.
I'm using version 14.0.7128.5000 (32-bit) and if I auto-increment dates, and if both dates used for the auto-increment have 12pm time in it, the auto-increment will lose 5 milliseconds per cell, at least that's what I get when trying to read those cells
on C# using openxml.  The values will show up normally on excel but when I convert them using FromOADate they will seem like they have one second less (but it's actually only 5 milliseconds less per cell dragged).
To reproduce this bug I use the following steps:
- Cell A2 - 10/19/2014 12:19 PM
- Cell A3 - 10/19/2014 12:18 PM
- Select both cells
- click on the little square on the bottom right of the cell selection
- drag it down
- try to read the fields A4 and below on C# using openxml
The first two cells written by hand will remain with the correct values but the cells A4 and below will "lose" 5 milliseconds for each cell.
Cells will display the correct value on excel but will have less milliseconds than they should for a FromOADate conversion.
The dates don't even need to be on the same day, you just need to have both dates having a 12PM time in it.
My locale is pt-BR or something, I can look into it more accurately if needed, in case you can't reproduce this bug.
Cheers.

Answer 1

If Excel is to slow for you, use database (MSSQL/MySQL/Oracle..or ACC), or work using VBA on array to paste in Worksheet when you done.
Oskar Shon, Office System MVP - www.VBATools.pl
if Helpful; Answer when a problem solved