Here is what i have done.

But it doesnt work.

Help please

def _totimestamp(self, cr, uid, ids, field_name, arg, context=None):

res = {}

for record in self.browse(cr, uid, ids, context=context):

res[record.id] = datetime.datetime.fromtimestamp(date_start)

return res

class project_cdr(osv.osv):

_name = 'project.cdr'

_description = 'Recuperation'

_columns = {

'project': fields.many2one('callity_project', string= 'Project_Name'),

'date_start': fields.datetime( 'Date Start', help='Date Start'),

'date_change': fields.function( _totimestamp,'Date change'),

'date_stop': fields.datetime( 'Date Stop', help='Date Stop'),

}

May be this will help you.

import datetime

datetime.datetime.fromtimestamp(SPECIFY FLOAT VALUE OF DATE)