A details explanation about the default date format strings can be found in this MSDN article.
The table below displays a list of the standard format characters supported by RadDateTimePicker. The format characters are case-sensitive; for example, 'f' and 'F' represent different patterns.
|Format Character||Associated Property/ Description|
|f||Full date and time (long date and short time)|
|F||FullDateTimePattern (long date and long time)|
|g||General (short date and short time)|
|G||General (short date and long time)|
|s||SortableDateTimePattern (based on ISO 8601) using local time|
|u||UniversalSortableDateTimePattern using the format for universal time display|
|U||Full date and time (long date and long time) using universal time|
The table below shows a list of patterns that can be combined to create custom patterns. The patterns are case-sensitive; for example, "MM" is recognized, but "mm" is not. If the custom pattern contains white-space characters or characters enclosed in single quotation marks, the output string will also contain those characters. Characters not defined as part of a format pattern or as format characters are reproduced literally.
|dd||The day of the month. Single-digit days will have a leading zero.|
|ddd||The abbreviated name of the day of the week, as defined in AbbreviatedDayNames.|
|M||The month, from 1 through 12.|
|MM||The numeric month. Single-digit months will have a leading zero.|
|MMM||The abbreviated name of the month, as defined in AbbreviatedMonthNames.|
|MMMM||The full name of the month, as defined in MonthNames.|
|y||The year without the century. If the year without the century is less than 10, the year is displayed with no leading zero.|
|yy||The year without the century. If the year without the century is less than 10, the year is displayed with a leading zero.|
|yyyy||The year in four digits, including the century.|
|gg||The period or era. This pattern is ignored if the date to be formatted does not have an associated period or era string.|
|h||The hour in a 12-hour clock. Single-digit hours will not have a leading zero.|
|hh||The hour in a 12-hour clock. Single-digit hours will have a leading zero.|
|H||The hour in a 24-hour clock. Single-digit hours will not have a leading zero.|
|HH||The hour in a 24-hour clock. Single-digit hours will have a leading zero.|
|m||The minute. Single-digit minutes will not have a leading zero.|
|mm||The minute. Single-digit minutes will have a leading zero.|
|s||The second. Single-digit seconds will not have a leading zero.|
|ss||The second. Single-digit seconds will have a leading zero.|
|t||The first character in the AM/PM designator defined in AMDesignator or PMDesignator, if any.|
|tt||The AM/PM designator defined in AMDesignator or PMDesignator, if any.|
It is possible to define your own format and set the RadDateTimePicker.Format property to Custom . Then, specify the desired CustomFormat, e.g. "dd/MM/yyyy".
this.radDateTimePicker1.Format = DateTimePickerFormat.Custom; this.radDateTimePicker1.CustomFormat = "yyyy/MM/dd";
Me.radDateTimePicker1.Format = DateTimePickerFormat.Custom Me.radDateTimePicker1.CustomFormat = "yyyy/MM/dd"