Disable text input after submit

Hi,

I got custom fields created with ACF on a custom post type. I got one custom field wich is a date picker. I would like it to be not editable after first save. i. e. first value entered and saved in this field will not be changed…

I triyed with jquery to change disabled property if the field is not empty when hitting save button but can’t fid a way to make it working..

Any ideas ?

Thanks