InfoPath: Update DateTime Field/Attribute using C#

Updating the Field/Attribute is rather easy, the problem is when that Field/Attribute is displayed in a date picker control. The reason for it is the format of the DateTime string. In order, InfoPath to parse out the datetime correctly from the Field/Attribute and display it correctly (pass validation) you have to use the following formats:

1. For displaying dates only:”yyyy-MM-dd”

2. For displaying date and time: “yyyy’-'MM’-'dd’T'HH’:'mm’:'ss”

So right before you set the value in the XPathNavigator field/attribute, convert the date you want to use to a string using one of the two formats above.

Example:

DateTime today=DateTime.Now;
XPathNavigator myfield=MainDataSource.CreateNavigator()
.SelectSingleNode("xpath to field",this.NamespaceManager);
String dateString=today.ToString("yyyy'-'MM'-'dd'T'HH':'mm':'ss");
myfield.SetValue(dateString);