I would like to use a date field in the calculation of a custom formula field. The field will be included in a  in Zoho CRM module.

 

The date field may sometimes be blank. If the field is blank I want to return 'true', if not then return 'false'

 

The following formula doesnt work but will hopefully illustrate what im trying to achieve

If(${Products.8. Position not proceeding}) = null,'a','b')

 

Thanks in advance