Format String

To build a custom format string you can use the format specifiers provided by Microsoft. The format specifiers are listed here: Format Specifiers.

If you want to add a specific content to the string you will need to enclose in with single quotes. Here is an example that shows this.

Using a custom format string

radTimeSpanPicker1.Format = "dd\'days \'hh\'hours \'mm\'minutes \'ss\'seconds \'fff\'milliseconds\'";

radTimeSpanPicker1.Format = "dd'days 'hh'hours 'mm'minutes 'ss'seconds 'fff'milliseconds'"

You can find in the screenshot below the obtained result.