Develop Reference

How do I change the value that a ComboBox gets from a DateTime?

I'm currently developing a Calendar application and I am storing a collection of DateTimes in a ComboBox. The current format of the string printed in the ComboBox drop down list is "Day/Month/Year Hours:Minutes" but I would like it to only display it in "Hours:Minutes" format, how would you change that?
EDIT:
I'd just like to clarify that the question was meant to be "How do I format the ComboBox" and not necessarily the DateTime.

The ComboBox has a FormatString property which you can use to specify how a value is displayed.
This is particularly useful when using data binding.
In your case you could try setting FormatString property to "HH:mm".

Have a look at DateTime.ToString(string format)

If you just want to change the DateTime to another Format use
DateTime dt = new DateTime(2014, 04, 01, 15, 10, 0); // Year, Month, Day, Hour, Minute, Second
string formattedDateTime = dt.ToShortTimeString();
Hope this helps ;)

You can change the format by using String.Format(string,DateTime) when adding the dates to the combobox. You can find a lot of examples here

Very Simple
DateTime.Now.ToString("HH:mm")

If you control the combobox, just use this convenience method in DateTime:
var exampleDate = System.DateTime.Now;
exampleDate.ToShortTimeString(); // will output hh:mm
If you instead need to override the ToString() method, as you mention in a comment, try:
exampleDate.ToString("hh:mm");
Note that there is a difference between hh:mm (hours up to 12) and HH:mm (hours up to 23). See the MSDN site for more details on formats etc.

format TimeSpan summary in stimulsoft

I'm creating simple table report with column of TimeSpan type.
I'm summing its values, which leads into values bigger than 24 hours, into Text componnent.
{SumTime(DataBand1,Records.time)}
I'm trying to format Text field like HH:mm:ss, but for 25 hours it gives me 01:00:00 (or 1.01:00:00 with general formatting) instead of 25:00:00 what is my goal.
Edit: The problem is not how to format timespan, but how to associate formatted value into Stimulsoft's Text component.

The Hours property has a maximum of 24h. You could format it yourself using String.Format and TimeSpan.TotalHours:
string text = string.Format("{0}:{1}:{2}",
(int) Records.time.TotalHours, // TotalHours is double
Records.time.Minutes,
Records.time.Seconds);

I know this is kind of an old question, but I stumbled upon it looking for a solution myself. Having done some digging, here's what I've come up with:
Assuming you already have a timespan variable (either setting it in the datasource, or having a variable set with DateDiff), you can format it with the following:
{string.Format("{0}:{1}:{2}",
(int) Variable1.TotalHours,
Variable1.Minutes,
Variable1.Seconds)}
Lets say you have two different fields (named Date1 and Date2) that you need to get the difference of, and don't feel like putting it into a variable:
{string.Format("{0}:{1}:{2}",
(int) DateDiff(Date2,Date1).TotalHours,
DateDiff(Date2,Date1).Minutes,
DateDiff(Date2,Date1).Seconds)}

Create custom DateTime format respective of locality in .NET C#

So this seems like an easy thing to do, but still has me stumped. I want to display a list of strings to my user, based off of a few file's creation dates. So basically, display a list of DateTimes. The challenge is that want to use a custom format (something like 5/6/13 12:01 PM) but I want he date part of that to display differently based on how you have your system displaying the date (ie. a Brit would display that date as 6/5/13).
I thought I could just build two strings (one for date and one for time) and make sure that they date is region-formatted, but there is no default option for 5/6/13 (only 5/6/2013):
http://msdn.microsoft.com/en-us/library/az4se3k1.aspx
Next I hoped maybe the DateTime.ToShortDateString() function would work, but it displays as 5/6/2013 as well.
I know I can use a completely custom format like this: DateTime.ToString("M/d/yy h:mm tt") but I don't want to fix the date with the month before the day.
I suppose if I can' figure anything out then I could just build a custom datetime for America and for Europe and then query the OS for what datetime they are displaying in. But that seems really excessive. Any thoughts?

You could retrieve the current ShortDate format from current culture, change it and use it with ToString()
var currentDate = DateTime.Now;
var shortDateFormat = CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern;
var newShortDateFormat = shortDateFormat.Replace("yyyy", "yy");
Console.WriteLine(currentDate.ToString(shortDateFormat));
Console.WriteLine(currentDate.ToString(newShortDateFormat));

System.Globalization.CultureInfo implements IFormatProvider, so you can provide a CultureInfo object as a parameter to the ToString method.
MSDN seems to have an example of exactly what you want.

Retrieve format of date from date value

I am receiving some data into a variable of type object. In certain cases this data are date values. For that data, I would like to convert this to a string and return it in the same format as it was passed. In some cases, the object could be a datetime, in others a date only or time only values.
As soon as I convert the object to a date or a string, it is obviously given a time of midnight which in my scenario may be a valid time (so I cannot test to see if the time is midnight in which case I could deduce that it would have been a date only date value, nor can I use regex on it as there will always be a time element).
Intellisense shows me it correctly, ie in the format I am wishing to return the value.
Is there an easy way to achieve this (hopefully without using reflection)
Many thx
Simon

Your question is a little unclear but I think you're looking for something like this:
DateTime result;
if (DateTime.TryParse(value, out result))
{
// use result here
}
In the above code value is a string that represents the data coming in. The code will only enter the if block if the string is a valid DateTime. At which point you can do the processing you need on it.

Im not sure i understand the question but i would recommend you to take a look at this conversion example on MSDN, and see the Documentation of the DateTime Structur it contains a lot of Conversion/Formatting Methods i hope it helps.

There are many way to do formatting on the datetime and one of the simple way is fetch the data from the required table in the desired format. Like here you need to display the date and if you your format is dd/MM/yyyy then try this
select Convert(varchar(10),StartDate,103) as StartDateformat from table where filtername=#filtername
use this link to find other format Cast and Convert
From local variable to DateTime Conversion
DateTime todateformat = Convert.ToDateTime(txttodate.Text.Trim());
From DateTime to local variable Conversion in specific format
string startdate = todateformat.ToString("dd/MM/yyyy hh:mm:ss");

DateTimePicker: pick both date and time

Is it possible to use DateTimePicker (Winforms) to pick both date and time (in the dropdown)? How do you change the custom display of the picked value? Also, is it possible to enable the user to type the date/time manually?

Set the Format to Custom and then specify the format:
dateTimePicker1.Format = DateTimePickerFormat.Custom;
dateTimePicker1.CustomFormat = "MM/dd/yyyy hh:mm:ss";
or however you want to lay it out. You could then type in directly the date/time. If you use MMM, you'll need to use the numeric value for the month for entry, unless you write some code yourself for that (e.g., 5 results in May)
Don't know about the picker for date and time together. Sounds like a custom control to me.

It is best to use two DateTimePickers for the Job
One will be the default for the date section and the second DateTimePicker is for the time portion. Format the second DateTimePicker as follows.
timePortionDateTimePicker.Format = DateTimePickerFormat.Time;
timePortionDateTimePicker.ShowUpDown = true;
The Two should look like this after you capture them
To get the DateTime from both these controls use the following code
DateTime myDate = datePortionDateTimePicker.Value.Date +
timePortionDateTimePicker.Value.TimeOfDay;
To assign the DateTime to both these controls use the following code
datePortionDateTimePicker.Value = myDate.Date;
timePortionDateTimePicker.Value = myDate.TimeOfDay;

Unfortunately, this is one of the many misnomers in the framework, or at best a violation of SRP.
To use the DateTimePicker for times, set the Format property to either Time
or Custom (Use Custom if you want to control the format of the time using
the CustomFormat property). Then set the ShowUpDown property to true.
Although a user may set the date and time together manually, they cannot use the GUI to set both.

DateTime Picker can be used to pick both date and time that is why it is called 'Date and Time Picker'. You can set the "Format" property to "Custom" and set combination of different format specifiers to represent/pick date/time in different formats in the "Custom Format" property. However if you want to change Date, then the pop-up calendar can be used whereas in case of Time selection (in the same control you are bound to use up/down keys to change values.
For example a custom format " ddddd, MMMM dd, yyyy hh:mm:ss tt " will give you a result like this : "Thursday, August 20, 2009 02:55:23 PM".
You can play around with different combinations for format specifiers to suit your need e.g MMMM will give "August" whereas MM will give "Aug"

Go to the Properties of your dateTimePickerin Visual Studio and set Format to Custom. Under CustomFormat enter your format. In my case I used MMMMdd, yyyy | hh:mm

You can get it to display time. From that you will probably have to have two controls (one date, one time) the accomplish what you want.

I'm afraid the DateTimePicker control doesn't have the ability to do those things. It's a pretty basic (and frustrating!) control. Your best option may be to find a third-party control that does what you want.
For the option of typing the date and time manually, you could build a custom component with a TextBox/DateTimePicker combination to accomplish this, and it might work reasonably well, if third-party controls are not an option.

If you need (24 hours) military time. You should use "HH" instead of "hh".
"MM/dd/yyyy HH:mm"