I want to create a column that split dates into "Before" and "After" a specific date. How is the date represented in a conditional statement?

[#1 · Accepted solution]

Hi @Huw_Nanomarket 

You can use the Make Binning Formula to achieve that without the need to create a formula yourself

1. Select the Date Column Go Cols > Utilities > Make Binning Formula

2. Define the Bins Add a cutpoint for your specific date (e.g. 09-2009) Label the bins as "Before" and "After" to represent the two groups.
   

   

   Click on the Make Formula Column and you are done. 
   
   Let me know if that answers your question.
   
   Spyros

[#2]

The functionality is also available via the right click - new Formula column menu.

The advantage of using the functionality via the Cols menu:
The new column is generated with the same same format settings as the input column. When the users clicks on  "Edit Binning Formula":

they can easily edit the binning:

For comparison: Edit Binning formula for a column that is generated via the new formula column menu:

[cutpoints in seconds]

[#3]

this issue got fixed in JMP19:

[#4]

still missing: Edit Binning Formula for Transform columns:

[#5]

Thanks for this. Very simple solution.

[#6]

In addition to Spyros answer there is also the possibility of using the "Parse Date"/"In Format" function

Date and Time Functions

or directly Writing writing the datetime.

Using dates, times, datetimes and durations in JMP

Names Default To Here( 1 );
way1 = Parse Date( "2025-10-30", "YYYY-MM-DD" );
way2 = 1Nov2025:12:30:25;

Show( way1, way2, way1 < way2 );

way1 = 30Oct2025;
way2 = 01Nov2025:12:30:25;
way1 < way2 = 1;

Kasper

[#7 · Accepted solution]

In addition to the Make Binning Formula, in JSL you can use a simple If() comparison with dates.  Here is a column formula that illustrates the how to do it

If( :Date >= Informat( "10/14/2025", "MDY" ),
	1,
	0
)