C# DateTime Format: Complete 2025 Cheat Sheet + 50+ Examples

C# DateTime class in C# provides properties and methods to format dates in different DateTime formats. This article explains how to work with the C# DateTime format, Including Timer and Sleep Methods.

Let’s start with C# DateTime Object–

DateTime is a Struct in the System namespace. It helps the developers to retrieve information about system date, time, month, year, or even the day of the week.

How To Create The C# DateTime Object?

class Program
    {
        static void Main(string[] args)
        {
            // Year, Month, Date
            DateTime dt = new DateTime(2016, 03, 07);
            Console.WriteLine(dt.ToString());
            Console.Read();

        }
    }

The output of the above program will be: 3/7/2016 12:00:00 AM

If you see here, in this output time is shown as 12:00:00 AM (default time). We haven’t set any time value, and thus the system automatically assigned default values to an hour, minute, and second.

DateTime Object Properties:

DateTime dt = new DateTime(2016, 03, 07);
            int year = dt.Year;
            int month = dt.Month;
            int date = dt.Day;
            int hour = dt.Hour;
            int min = dt.Minute;
            int sec = dt.Second;
            int dayOfWeek = Convert.ToInt32(dt.DayOfWeek);
            int dayOfYear = dt.DayOfYear;

Year

Year property retrieves the year component of the date represented by the date-time instance. It returns an integer value expressed as a value between 1 and 9999.

Month

Month property retrieves the month component of the date represented by the date-time instance. It returns an integer value expressed as a value between 1 and 12.

Day

Day property retrieves the date component of the month represented by the date-time instance. It returns an integer value expressed as a value between 1 and 31.

Hour

Hour property retrieves the hour component of the date represented by the date-time instance. It returns an integer value expressed as a value between 0 and 23.

Minute

Min property retrieves the minute component of the date represented by the date-time instance. It returns an integer value expressed as a value between 0 and 59.

Second

Second property retrieves the second component of the date represented by the date-time instance. It returns an integer value expressed as a value between 0 and 59.

Day of the Week

Day of the week property retrieves the enumerated constant that indicates the day of the week represented by the date-time object. It also requires casting to accept an integer value.

Day of Year

Day of year property retrieves the day of the year represented by the date-time object. It returns an integer value expressed as a value between 0 and 366.

Now let’s have a look at the code below to see how we can use these properties.

DateTime dt = new DateTime(2016, 03, 07);
            int year = dt.Year;
            int month = dt.Month;
            int date = dt.Day;
            int hour = dt.Hour;
            int min = dt.Minute;
            int sec = dt.Second;
            int dayOfWeek = Convert.ToInt32(dt.DayOfWeek);
            int dayOfYear = dt.DayOfYear;

            Console.WriteLine(year);
            Console.WriteLine(month);
            Console.WriteLine(date);

            Console.WriteLine(hour);
            Console.WriteLine(min);
            Console.WriteLine(sec);

            Console.WriteLine(dayOfWeek);
            Console.WriteLine(dayOfYear);

            Console.Read();

The output of the above program will be:

Year: 2016
Month : 3
Date: 7

Hour : 0
Minute : 0
Second : 0

Day of the week: 1
Day of the year: 67

How To Get the Current Date and Time?

DateTime object contains a number of different methods to access the system time. The “Now” method allows you to get the current system time/date and even allows you to operate on it.

Syntax:

DateTime dt = DateTime.Now;

We can easily convert it to a string to get the current date-time, or we can even change the format of the date by using the formats below.

NOTE: Consider the current date and time is 7 March 2025 11:06:25

Display date and time in 24-hour format

DateTime.Now.ToString(“dd/MM/yyyy HH:mm:ss”);

Ans :07/03/2025 11:06:25
Note: HH is used for 24 24-hour format.
           hh for 12 hour format

Display am/pm in the date and time or 12-hour format.

 DateTime.Now.ToString(“hh:mm:ss tt”);

 Ans:11:06:25 AM
 Note: “tt” for AM or PM

Display the time zone in the date and time.

DateTime.Now.ToString(“hh:mm:ss tt zzz”);

Ans: 11:06:25 AM +05:30 (Here +05:30 is the time zone for India)
Note: zzz is used to display the time zone.

Show the full month name in the date.

DateTime.Now.ToString(“dd-MMMM-yy”);

Ans: 07-March-16

How to format a full day name in a date?

DateTime.Now.ToString(“dddd-MMMM-yy”);

Ans: Monday-March-16
Note: MMMM for full month name

How to format the full Year name in a date?

DateTime.Now.ToString (“dddd-MMMM-yyyy”);

Ans: Monday-March-2016
Note: yyyy for four-digit year

To reduce/subtract date or days

DateTime.Now.AddDays(-10)

To add days

DateTime.Now.AddDays(10)

C# DateTime to “YYYYMMDDHHMMSS” format

DateTime.Now.ToString (“yyyyMMddHHmmss”);

You can convert the dateTime to any DateTime format by simply adding the required format in ToString (.ToString(“yyyyMMdd”)) as shown in the above example. Please note that C# datetime format is case-sensitive. Please check below.

y = year, m = minutes / M = months, d= date, h = 12 hour, H = 24 hour, s= seconds

Let’s have a look at below C# DateTime formats and their outputs. Here we see all the patterns of the C# DateTime, format, and outputs.

C# DateTime Formatting Best Practices

1. Always Specify Culture for Persistent Storage

// For storage/transmission, use invariant culture
string dbFormat = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture);

// For display, use current culture
string userFormat = DateTime.Now.ToString("F", CultureInfo.CurrentCulture);

2. Performance Optimization for High-Volume Formatting

// Cache formatters for repeated use
var formatter = new StringBuilder(32);
for (int i = 0; i < 1000; i++) {
    formatter.Clear();
    formatter.Append(DateTime.Now.Year).Append("-")
             .Append(DateTime.Now.Month.ToString("00")).Append("-")
             .Append(DateTime.Now.Day.ToString("00"));
    // Use formatter.ToString()
}

Let’s look at the sample C# code below that uses these C# datetime formats.

namespace DateTimeFormat
{
    class Program
    {
        static void Main(string [] args)
        {
            // dt erpresents DateTime object.
            // Here DateTime is a Struct in the System namespace.
                                     //year,month,date,hour,minute,seconds
            DateTime dt = new DateTime(2016, 03, 07, 11, 06, 25);
            Console.WriteLine("Date: " + dt.ToString());

            // Datetime in different formats 
            Console.WriteLine("***Datetime in different formats***");
            Console.WriteLine(dt.ToString("dd/MM/yyyy"));
            Console.WriteLine(dt.ToString("dd-MM-yyyy"));
            Console.WriteLine(dt.ToString("MM/dd/yyyy"));
            Console.WriteLine(dt.ToString("MM-dd-yyyy"));
            Console.WriteLine(dt.ToString("dddd, dd MMMM yyyy"));
            Console.WriteLine(dt.ToString("dddd, dd MMMM yyyy HH:mm:ss"));
            Console.WriteLine(dt.ToString("yyyyMMddHHmmss"));
            Console.WriteLine(dt.ToString("HH:mm"));
            Console.WriteLine(dt.ToString("dd/MM/yyyy HH:mm"));
            Console.WriteLine(dt.ToString("HH:mm:ss"));
            Console.WriteLine(dt.ToString("dd/MM/yyyy HH:mm:ss"));
            Console.WriteLine(dt.ToString("hh:mm tt"));
            Console.WriteLine(dt.ToString("dd/MM/yyyy hh:mm tt"));
            Console.WriteLine(dt.ToString("H:mm"));
            Console.WriteLine(dt.ToString("dd/MM/yyyy H:mm"));
            Console.WriteLine(dt.ToString("h:mm tt"));
            Console.WriteLine(dt.ToString("MM/dd/yyyy h:mm tt"));
            Console.WriteLine(dt.ToString("MMMM dd"));
            Console.WriteLine(dt.ToString("yyyy-MM-dd HH:mm:ss.fffffffK"));
            Console.WriteLine(dt.ToString("ddd, dd MMM yyy HH:mm:ss 'GMT'"));
             Console.WriteLine(dt.ToString("yyyy-MM-dd HH:mm:ss"));
            Console.WriteLine(dt.ToString("yyyy MMMM"));

            Console.ReadLine();

        }
    }
}

The output of the above program will be something like this:

The following table describes various C# DateTime formats and their results. Here we see all the patterns of the C# DateTime format, and the results.

What Is the Sleep Method?

The sleep method is used to pause the running thread for a specific time span. It accepts time in milliseconds. Sleep is very useful in a multi-threading environment where you want one thread to stop to make way for other threads to complete their execution.

Syntax

System.Threading.Thread.Sleep(1000);

Parsing Strings to DateTime in C#

In many real-world scenarios, dates are received as strings — from APIs, databases, or user input. C# provides multiple ways to safely convert these strings into DateTime objects.

✅ Using DateTime.Parse

DateTime.Parse() converts a valid date string into a DateTime object. It throws an exception if the string is not in a recognized format.

Example – Valid Input

string dateStr = "2025-04-28";
DateTime parsedDate = DateTime.Parse(dateStr);
Console.WriteLine(parsedDate);  // Output: 4/28/2025 12:00:00 AM

⚠️ Example – Invalid Input (throws exception)

string invalidDate = "not a date";
DateTime parsed = DateTime.Parse(invalidDate); // Throws FormatException

Use this method only when you’re sure the input is valid, or you’re ready to handle exceptions.

✅ Using DateTime.TryParse

DateTime.TryParse() is safer. It returns true if parsing succeeds, and false if it fails — without throwing an exception.

Example – Safe Parsing

string input = "April 28, 2025";
DateTime result;
bool success = DateTime.TryParse(input, out result);

if (success)
    Console.WriteLine(result);  // Output: 4/28/2025 12:00:00 AM
else
    Console.WriteLine("Invalid date format.");

Example – Invalid Input (fails gracefully)

string badInput = "XYZ date";
bool parsed = DateTime.TryParse(badInput, out DateTime output);

Console.WriteLine(parsed); // Output: False

🌍 Culture Considerations

Parsing is culture-sensitive by default. For consistent results (e.g. on US vs EU systems), specify a culture:

string euDate = "28/04/2025";
var culture = new CultureInfo("en-GB");
DateTime d = DateTime.Parse(euDate, culture);

📝 Summary

📅 Standard DateTime Format Specifiers (C#)

🛠️ Custom DateTime Format Specifiers (C#)

✅ Pro Tip: Combine custom specifiers like "yyyy-MM-dd HH:mm:ss" for formats like 2025-04-28 14:45:30.

DateTime Formatting FAQs

What’s the best format for JSON APIs?

Use the round-trip ("o") format: DateTime.Now.ToString("o") → 2024-03-26T14:30:45.1234567Z

How to format dates for multiple cultures?

Cache CultureInfo instances for performance:

// German format
  var german = CultureInfo.GetCultureInfo("de-DE");
  Console.WriteLine(DateTime.Now.ToString("F", german));

Conclusion

In this article, we have learned about the DateTime class. A DateTime object is used to gather information about the date and time of the system or to set a custom date and time for use in a particular application requirement.

Date and Time in C# are handled by DateTime class in C# that provides properties and methods to format dates in different C# DateTime formats.

We also learned about the Sleep method, which is part of the System.Threading and is used to pause the execution for a certain time interval. This allows the programmers to start another thread in a multi-threading environment while the previous thread is paused.