How to check if a date field is null in Nintex Form

@guru2000 if you don't want your user to leave it empty then make that column which is connected to your date control as required.

Also, on the date control, if you open the control setting then under Validation, there is an option Required.

Thanks Kunal, Here is what I want,

I want the date field to be required based on a condition. Sometimes the date field is required and other times it is not.

What kind of rule do I need.

@guru2000 you need to use the validation rule. Try using with If function. Also, I don't know what's your condition so couldn't help you much.

@guru2000 I'm little confused !!!! If you want to use Isnullorempty then it means under no circumstances user can leave that empty, if that's your requirements then below are 3 different ways to do it:

1. Make connected SharePoint column as required
2. Go to control's settings and expand validation and make it required (you won't get named control tab when you use expression choice in required dropdown)
3. Create a rule on the right side for the date control using "{Self}" from named control and Isnullorempty function apply the rule (see below screenshot)
   
   

    

   

    

But, if the date control is required based on some other control's value then you need to tweak above option # 3 accordingly.