In data tables, JMP can accept the input of date-time values in one format (the input format), store them internally as the number of seconds since the base date, and display them in a different date-time format. The Informat() and Format() functions give you this control.
Informat() takes a string date-time value, defines the date format used in that string, and returns the date in ddMonyyyy format.
Informat( "19May2011 11:37:52 AM", "ddMonyyyy h:m:s" );
19May2011:11:37:52
Format() takes the number of seconds since the base date (or a date-time function that returns that number) and returns the date in the specified format.
Format( 3388649872, "ddMonyyyy h:m:s" );
"19May2011 11:37:52 AM"
Format( Today(), "ddMonyyyy h:m:s" );
"19May2011 11:37:52 AM"
Suppose that you are entering dates into a column using the d/m/y h:m format, but you want to see the dates in the m/d/y format. The Informat() function defines the input format, and the Format() function defines the display format. For example,
New Table( "Widget Assembly",
	Add Rows( 1 ),
	New Column( "Date",
		Numeric,
		"Continuous",
		Format( "m/d/y" ),
		Informat( "d/m/y h:m" ),
		Set Values( [3126917100] )
	)
);
The Format() and Informat() values are shown in the data table’s column properties (Example of Date-Time Display and Input Values). Note that when you click in the cell to edit it, the date-time value appears in the input format. When you edit the value, or add a new value, the format specified in the data table column Format list is used to display the value.
Example of Date-Time Display and Input Values
Notes: 
Date-Time Formats describes the formats used as arguments in date-time functions or as data table formats. You can also use the formats for the format argument to a Format message to a data column. See Set or Get Formats.
"m/d/y"
"01/02/1999"
"mmddyyyy"
"01021999"
"m/y"
"01/1999"
"d/m/y"
"02/01/1999"
"ddmmyyyy"
"02011999"
"ddMonyyyy"
"02Jan1999"
"Monddyyyy"
"Jan021999"
"y/m/d"
"1999/01/02"
"yyyymmdd"
"19990102"
"yyyy-mm-dd"
“1999-01-02“
"yyyyQq"
1999Q1
"m/d/y h:m"
"01/02/1999 13:01"
"01/02/1999 1:01 PM"
"m/d/y h:m:s"
"01/02/1999 13:01:55"
"01/02/1999 1:01:55 PM"
"d/m/y h:m"
"02/01/1999 13:01"
"02/01/1999 1:01 PM"
"d/m/y h:m:s"
"02/01/1999 13:01:55"
"02/01/1999 1:01:55 PM"
"y/m/d h:m"
‘1999/01/02 13:01’
‘1999/01/02 1:01 PM’
"y/m/d h:m:s"
‘1999/01/02 13:01:02
‘1999/01/02 1:01:02 PM’
"ddMonyyyy h:m"
"02Jan1999 13:01"
"02Jan1999 1:01 PM"
"ddMonyyyy h:m:s"
"02Jan1999 13:01:02"
"02Jan1999 1:01:02 PM"
"ddMonyyyy:h:m"
"02Jan1999:13:01"
"02Jan1999:1:01 PM"
"ddMonyyyy:h:m:s"
"02Jan1999:13:01:02"
"02Jan1999:1:01:02 PM"
"Monddyyyy h:m"
"Jan021999 13:01"
"Jan021999 1:01 PM"
"Monddyyyy h:m:s"
"Jan021999 13:01:02"
"Jan021999 1:01:02 PM"
":day:hr:m"
"34700:13:01"
":33:001:01 PM"
":day:hr:m:s"
"34700:13:01:02"
":33:001:01:02 PM"
"h:m:s"
"13:01:02"
"01:01:02 PM"
"h:m"
"13:01"
"01:02 PM"
"yyyy-mm-ddThh:mm"
1999-01-02T13:01
"yyyy-mm-ddThh:mm:ss"
1999-01-02T13:01:02
":day:hr:m"
“52:03:01”
":day:hr:m:s"
“52:03:01:30”
"hr:m"
“17:37”
"hr:m:s"
“17:37:04”
"min:s"
“37:04”
"Date Abbrev"
(Display only) “01/02/1999"
"Date Long"
(Display only) "Saturday, January 02, 1999"
“Locale Date”
(Display only) “01/02/1999"
“Locale Date Time h:m”
(Display only) “01/02/1999 13:01“ or “01/02/1999 01:01 PM“
“Locale Date Time h:m:s”
(Display only) “01/02/1999 13:01:02“ or “01/02/1999 01:01:02 PM“