I want to format the input string into MM/dd/yyyy hh:mm:ss format in C#.
The input string is in format MM/dd/yyyy hh:mm:ss
For example :
You can use DateTime.ParseExact() method.
Converts the specified string representation of a date and time to its DateTime equivalent using the specified format and culture-specific format information. The format of the string representation must match the specified format exactly.
DateTime date = DateTime.ParseExact("04/30/2013 23:00",
"MM/dd/yyyy HH:mm",
CultureInfo.InvariantCulture);
Here is a DEMO.
hh is for 12-hour clock from 01 to 12, HH is for 24-hour clock from 00 to 23.
For more information, check Custom Date and Time Format Strings