Date fields do a validation check on blur even when validateOnBlur is set to false.

I used code from the Ext.form.Panel api documentation to demonstrate.

Code:
 
Ext.create('Ext.form.Panel', {    title: 'Simple Form',
    bodyPadding: 5,
    width: 350,


    // The form will submit an AJAX request to this URL when submitted
    url: 'save-form.php',


    // Fields will be arranged vertically, stretched to full width
    layout: 'anchor',
    defaults: {
        anchor: '100%'
    },


    // The fields
    defaultType: 'datefield',
    items: [{
        fieldLabel: 'TestDate1',
        name: 'date1',
        allowBlank: false,
        validateOnBlur: false
    },{
        fieldLabel: 'TestDate2',
        name: 'date2',
        allowBlank: false
    }],


    // Reset and Submit buttons
    buttons: [{
        text: 'Reset',
        handler: function() {
            this.up('form').getForm().reset();
        }
    }, {
        text: 'Submit',
        formBind: true, //only enabled once the form is valid
        disabled: true,
        handler: function() {
            var form = this.up('form').getForm();
            if (form.isValid()) {
                form.submit({
                    success: function(form, action) {
                       Ext.Msg.alert('Success', action.result.msg);
                    },
                    failure: function(form, action) {
                        Ext.Msg.alert('Failed', action.result.msg);
                    }
                });
            }
        }
    }],
    renderTo: Ext.getBody()
});