Can you give me an example ?

if you can add a onchange and domain,do like this

@api.onchange('partner_id')

def apply_domain_customer(self):

vehicles = self.env['fleet.vehicle'].search([('driver_id', '=',

self.partner_id.id)]).ids

return {

'domain': {

'vehicle': [('id', 'in', vehicles)]

}}

you can get date using datetime library in python

datetime.now()

and

from dateutil.relativedelta import relativedelta

new_date = old_date + relativedelta(years=5)

thanks for your answer