<field name="working_hours"  attrs="{'invisible': [('field name ', '=', False)]}"/>

You can do this by using attrs field invisible now you just need to set condition field_name = False or field_name != False . Like this that working hours field will be hidden or will be displayed on based on condition.

Thanks. 

You Can hide a field or Button using below code , its work for me  and i'm using odoo version 9

here i'm hidding a button using which i'm checking a field(work_email) value is emty or not

my py file ( here i'm using inherited view of hr employee )

work_email = fields.Char('Work Email')
hide = fields.Boolean(string='Hide', compute="_compute_hide" ,store=False)

@api.depends('work_email')

def _compute_hide(self):

if not self.work_email:

self.hide = True

else:

self.hide = False

my xml file

<button class="oe_stat_button" name="send_personal_mail" string="Send Email"  type="object" icon="fa-envelope" attrs="{'invisible': [('hide','=', True)]}" /> 

<field name="hide" invisible="1" />

i added the field before the function without depends or onchange and it works now automatically .. like this example:

class InheritHrEmployee(models.Model):
    _inherit = 'hr.employee'

    inv = fields.Boolean(string="Invisible", compute="c_inv", store=False)

    @api.one
    def c_inv(self):
        if self.env.uid == self.user_id.id or self.env.uid == self.parent_id.user_id.id or self.env.user.has_group(
                 'hr.group_hr_user'):
            self.inv = False
        else:
            self.inv = True