[c#] Adding a Time to a DateTime in C#

I have a calendar and a textbox that contains a time of day. I want to create a datetime that is the combination of the two. I know I can do it by looking at the hours and mintues and then adding these to the calendar DateTime, but this seems rather messy.

Is there a better way?

Using https://github.com/FluentDateTime/FluentDateTime

DateTime dateTime = DateTime.Now;
DateTime combined = dateTime + 36.Hours();
Console.WriteLine(combined);

Combine both. The Date-Time-Picker does support picking time, too.

You just have to change the Format-Property and maybe the CustomFormat-Property.

   DateTime newDateTime = dtReceived.Value.Date.Add(TimeSpan.Parse(dtReceivedTime.Value.ToShortTimeString()));

If you are using two DateTime objects, one to store the date the other the time, you could do the following:

var date = new DateTime(2016,6,28);

var time = new DateTime(1,1,1,13,13,13);

var combinedDateTime = date.AddTicks(time.TimeOfDay.Ticks);

An example of this can be found here

Depending on how you format (and validate!) the date entered in the textbox, you can do this:

TimeSpan time;

if (TimeSpan.TryParse(textboxTime.Text, out time))
{
   // calendarDate is the DateTime value of the calendar control
   calendarDate = calendarDate.Add(time);
}
else
{
   // notify user about wrong date format
}

Note that TimeSpan.TryParse expects the string to be in the 'hh:mm' format (optional seconds).