Right, which is why an understanding of how .NET handles the calculations is important. If it's important that you preserve things like "last day of the month"

Right, which is why an understanding of how .NET handles the calculations is important. If it's important that you preserve things like "last day of the month" there are libraries[0] which support this and will do date calculations accordingly. [0] For example: http://sourceforge.net/projects/dday-ical/ http://sourceforge.net/projects/dday-ical/