A date and time format string defines the text representation of a DateTime value that results from a formatting operation. It can also define the representation of a date and time value that is required in a parsing operation in order to successfully convert the string to a date and time. A custom format string consists of one or more custom date and time format specifiers. Any string that is not a standard date and time format string is interpreted as a custom date and time format string.
Let’s apply a custom format string to the OrderDate field of Orders controller.
Start the Project Designer. In the Project Explorer, double-click on Orders / Fields / OrderDate field node.
Change the Data Format String property:
| Property | Value | 
| Data Format String | 'The' d 'of' MMMM, yyyy. | 
Press OK to save the field. On the toolbar, press Browse.
Navigate to the Orders page. The Order Date values will be rendered in the custom date pattern.
Below is a list of supported custom date format strings.
| Format specifier | Description | Examples | 
| "d" | The day of the month, from 1 through 31. | 6/1/2009 1:45:30 PM –> 1             | 
| "dd" | The day of the month, from 01 through 31. | 6/1/2009 1:45:30 PM –> 01             | 
| "ddd" | The abbreviated name of the day of the week. | 6/15/2009 1:45:30 PM -> Mon (en-US)             | 
| "dddd" | The full name of the day of the week. | 6/15/2009 1:45:30 PM -> Monday (en-US)             | 
| "f" | The tenths of a second in a date and time value. | 6/15/2009 13:45:30.617 –> 6             | 
| "ff" | The hundredths of a second in a date and time value. | 6/15/2009 13:45:30.617 -> 61 6/15/2009 13:45:30.005 -> 00 | 
| "fff" | The milliseconds in a date and time value. | 6/15/2009 13:45:30.617 –> 617             | 
| "ffff" | The ten thousandths of a second in a date and time value. | 6/15/2009 13:45:30.6175 –> 6175             | 
| "fffff" | The hundred thousandths of a second in a date and time value. | 6/15/2009 13:45:30.61754 –> 61754             | 
| "ffffff" | The millionths of a second in a date and time value. | 6/15/2009 13:45:30.617542 –> 617542             | 
| "fffffff" | The ten millionths of a second in a date and time value. | 6/15/2009 13:45:30.6175425 –> 6175425             | 
| "g", "gg" | The period or era. | 6/15/2009 1:45:30 PM -> A.D. | 
| "h" | The hour, using a 12-hour clock from 1 to 12. | 6/15/2009 1:45:30 AM –> 1             | 
| "hh" | The hour, using a 12-hour clock from 01 to 12. | 6/15/2009 1:45:30 AM –> 01             | 
| "H" | The hour, using a 24-hour clock from 0 to 23. | 6/15/2009 1:45:30 AM –> 1             | 
| "HH" | The hour, using a 24-hour clock from 00 to 23. | 6/15/2009 1:45:30 AM –> 01             | 
| "m" | The minute, from 0 through 59. | 6/15/2009 1:09:30 AM –> 9             | 
| "mm" | The minute, from 00 through 59. | 6/15/2009 1:09:30 AM –> 09             | 
| "M" | The month, from 1 through 12. | 6/15/2009 1:45:30 PM -> 6 | 
| "MM" | The month, from 01 through 12. | 6/15/2009 1:45:30 PM -> 06 | 
| "MMM" | The abbreviated name of the month. | 6/15/2009 1:45:30 PM -> Jun (en-US)             | 
| "MMMM" | The full name of the month. | 6/15/2009 1:45:30 PM -> June (en-US)             | 
| "s" | The second, from 0 through 59. | 6/15/2009 1:45:09 PM -> 9 | 
| "ss" | The second, from 00 through 59. | 6/15/2009 1:45:09 PM -> 09 | 
| "t" | The first character of the AM/PM designator. | 6/15/2009 1:45:30 PM -> P (en-US)             | 
| "tt" | The AM/PM designator. | 6/15/2009 1:45:30 PM -> PM (en-US)             | 
| "y" | The year, from 0 to 99. | 1/1/0001 12:00:00 AM –> 1             | 
| "yy" | The year, from 00 to 99. | 1/1/0001 12:00:00 AM –> 01             | 
| "yyyy" | The year as a four-digit number. | 1/1/0001 12:00:00 AM –> 0001             | 
| "z" | Hours offset from UTC, with no leading zeros. | 6/15/2009 1:45:30 PM -07:00 -> -7 | 
| "zz" | Hours offset from UTC, with a leading zero for a single-digit value. | 6/15/2009 1:45:30 PM -07:00 -> -07 | 
| "zzz" | Hours and minutes offset from UTC. | 6/15/2009 1:45:30 PM -07:00 -> -07:00 | 
| ":" | The time separator. | 6/15/2009 1:45:30 PM -> : (en-US)             | 
| "/" | The date separator. | 6/15/2009 1:45:30 PM -> / (en-US)             | 
| 'string' | Literal string delimiter. | 6/15/2009 1:45:30 PM ('arr:' h:m t) -> arr: 1:45 P | 
| % | Defines the following character as a custom format specifier. | 6/15/2009 1:45:30 PM (%h) -> 1 | 
| Any other character | The character is copied to the result string unchanged. | 6/15/2009 1:45:30 AM (arr hh:mm t) -> arr 01:45 A |