C# Parsing DateTime Unable to Convert String to DateTime

Question

I followed the string output of my date variable, and parsed according to the format, but still encountered an Format Exception.

May I know what should I change?

string DOB = retrieved.Entities[i].GetAttributeValue<AliasedValue>("Contact.birthdate").Value.ToString();
//output: 4/13/2018 12:00:00AM

DateTime DOB_formatted = DateTime.ParseExact(DOB, "MM/dd/yyyy", null);
//System.FormatException

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Resolution: Convert Object to DateTime

DateTime DOB_formatted = Convert.ToDateTime(retrieved.Entities[i].GetAttributeValue<AliasedValue>("Contact.birthdate").Value);

Answer 1

ParseExact() requires a perfect match. The MM/dd/yyyy format string would require 04/13/2018 , but the value is 4/13/2018 12:00:00AM . You want M/d/yyyy hh:mm:sstt , and you should confirm day values don't have leading zeroes. There's also an overload that takes an array of format strings , if you can't trust the data source to be consistent.

Finally, per the comments, the compile-time type of Value is Object . But what about run-time? There's still a good chance the run-time type is already a DateTime value, and all you need to do is cast it. Because of internationalization/culture issues, converting to string and then re-parsing back to DateTime is suprisingly expensive. Avoiding those conversions will save the computer a ton of work, and really help performance.