is there a way to set a date field with a empty value. everytime i save a record, i get this error if there are no values -

You entered 'null' into a field where a calendar date was expected

Is date field mandatory.

no

I can set it null by workflow how you are trying to set it null.

actually it only happens if the field is hidden on the form. i have to display it and give it a empty string (with a space) field label just to work,