You don't need string manipulation to get a DateTime without the time part, just use [DateTime.Date](https://msdn.microsoft.com/en-us/library/system.datetime.date(v=vs.110).aspx). 

To get the time span between two dates, just subtract one from the other. Subtracting one date from another returns a [TimeSpan](https://msdn.microsoft.com/en-us/library/system.timespan(v=vs.110).aspx) object whose [Days](https://msdn.microsoft.com/en-us/library/system.timespan.days(v=vs.110).aspx) property is the difference in full dates.

All you need to do is :

    Dim days As Integer =(date2.Date-date1.Date).Days 

This way you avoid generating and parsing temporary strings.



The [`DateDiff`][1] function reports Day Intervals on a 24 hour basis, which provides an odd result when asking how many days ago something happened when the time of day changes.

For example, if I want to get the number of days since yesterday afternoon, if it hasn't been a full 24 hours, DateDiff will return `0`, whereas most of the time I ask that question, I'm expecting yesterday to be treated as 1 day ago, regardless of timestamp.

Is there a way to get DateDiff to return the number of calendar days?

### [Demo in .NET Fiddle][2]



	Dim date1 As DateTime = #3/1/2017 5:00 PM#
	Dim date2 As DateTime = #3/2/2017 10:00 AM#
	
	Dim daysAgo = DateDiff(DateInterval.Day, date1, date2)
	Dim msg = String.Format("Last date was {0} day(s) ago on {1}. ", daysAgo, date1.ToShortDateString())
	Console.WriteLine(msg) ' Last date was 0 day(s) ago on 3/1/2017. 

The following questions on StackOverflow do not address this nuance:

* [Get date difference in VB.NET][SO1]
* [Calculating Number of Months between 2 dates][SO2]
* [How to find the number of days between two dates / DateTimePickers][SO3] 


[1]: https://msdn.microsoft.com/en-us/library/ms127413.aspx
[2]: https://dotnetfiddle.net/sZdyMN

[SO1]: https://stackoverflow.com/q/20635037/1366033
[SO2]: https://stackoverflow.com/q/3249968/1366033
[SO3]: https://stackoverflow.com/q/19017466/1366033