Converting a String to DateTime

Question

How do you convert a string such as 2009-05-08 14:40:52,531 into a DateTime?

Answer 1

string input;
DateTime db;
Console.WriteLine("Enter Date in this Format(YYYY-MM-DD): ");
input = Console.ReadLine();
db = Convert.ToDateTime(input);

//////// this methods convert string value to datetime
///////// in order to print date

Console.WriteLine("{0}-{1}-{2}",db.Year,db.Month,db.Day);

Answer 2

Since you are handling 24-hour based time and you have a comma separating the seconds fraction, I recommend that you specify a custom format:

DateTime myDate = DateTime.ParseExact("2009-05-08 14:40:52,531", "yyyy-MM-dd HH:mm:ss,fff",
                                       System.Globalization.CultureInfo.InvariantCulture);

Answer 3

DateTime.Parse

Syntax:

DateTime.Parse(String value)
DateTime.Parse(String value, IFormatProvider provider)
DateTime.Parse(String value, IFormatProvider provider, DateTypeStyles styles)

Example:

string value = "1 January 2019";
CultureInfo provider = new CultureInfo("en-GB");
DateTime.Parse(value, provider, DateTimeStyles.NoCurrentDateDefault););

• Value: string representation of date and time.
• Provider: object which provides culture specific info.
• Styles: formatting options that customize string parsing for some date and time parsing methods. For instance, AllowWhiteSpaces is a value which helps to ignore all spaces present in string while it parse.

It's also worth remembering DateTime is an object that is stored as number internally in the framework, Format only applies to it when you convert it back to string.

• Parsing converting a string to the internal number type.

• Formatting converting the internal numeric value to a readable string.

I recently had an issue where I was trying to convert a DateTime to pass to Linq what I hadn't realised at the time was format is irrelevant when passing DateTime to a Linq Query.

DateTime SearchDate = DateTime.Parse(searchDate);
applicationsUsages = applicationsUsages.Where(x => DbFunctions.TruncateTime(x.dateApplicationSelected) == SearchDate.Date);

Full DateTime Documentation

Answer 4

try this

DateTime myDate = DateTime.Parse(dateString);

a better way would be this:

DateTime myDate;
if (!DateTime.TryParse(dateString, out myDate))
{
    // handle parse failure
}

Answer 5

Do you want it fast?

Let's say you have a date with format yyMMdd.

The fastest way to convert it that I found is:

var d = new DateTime(
(s[0] - '0') * 10 + s[1] - '0' + 2000, 
(s[2] - '0') * 10 + s[3] - '0', 
(s[4] - '0') * 10 + s[5] - '0')

Just, choose the indexes according to your date format of choice. If you need speed probably you don't mind the 'non-generic' way of the function.

This method takes about 10% of the time required by:

var d = DateTime.ParseExact(s, "yyMMdd", System.Globalization.CultureInfo.InvariantCulture);