How to save the time in a variable apart from the system time?

Time does not have format. It is represented by the structure System.DateTime without any strings, in a binary form, exactly as it should be. You should understand how to work with data, not with strings representing data. If you need remember some point of time, you should store this time as System.DateTime. You should use date-time formats only when you need to present time on screen in text form, which is, strictly speaking, is not a must: you could show some kind of calendar or purely graphical watch. Only when presented on screen (or in similar situations), this data should be presented in the culture-dependent manner.

Further steps depend on what do you mean by "save". If you mean saving in some persistent storage like a file or a database, you will need some persistent presentation, but this has nothing to do with what you show on screen and hence with date-time formats. It should be saved in some culture-independent format, such as RFC1123, sortable or universal sortable patterns, please see:
http://msdn.microsoft.com/en-us/library/az4se3k1.aspx[^].

Normally, you do it not "manually", but using one or another data-agnostic serializer, which takes care about presentation detail for you. On approach I would recommend is based on Data Contract. Please see:
http://msdn.microsoft.com/en-us/library/ms733127.aspx[^].

—SA

The alternate solution is, you can use String or Integer values.

Strings can be stored as a string and when you want to consube/cast date you can convert string to Date.

Every Date has an integer value representation in various form.

DateTime.Now.Ticks : Gives total ticks in nenoseconds for specified date from beginning, and a single tick represent 10000 miliseconds. It gives ticks from January 1, 0001.

DateTime.Now.ToBinary() : Returns date value in Binary format, you can store this in other variable and from this binary value you can retrive date at any time.

There are few more ways but I think this is enough for you now. Refer http://msdn.microsoft.com/en-us/library/03ybds8y[^] for more details on DateTime structure.

Thanks
Rushikesh Joshi

You can use if you do not want use Format datetime in C# support

 public static void FormatDateTimeUS()
{           
       CultureInfo culture = new CultureInfo("en-US", true);
       DateTimeFormatInfo dfi = (DateTimeFormatInfo)culture.DateTimeFormat.Clone();

       dfi.ShortDatePattern = "MM/dd/yyyy";
       dfi.LongDatePattern = "MM/dd/yyyy";
       dfi.FullDateTimePattern = "MM/dd/yyyy";

       culture.DateTimeFormat = dfi;
       Application.CurrentCulture = culture;          
}