let date ?(editable=true) ?(expand=true) ?help ?(f=(fun _ -> ()))
?(f_string=(fun(d,m,y)-> Printf.sprintf "%d/%d/%d" y (m+1) d))
label v =
Date_param
{
date_label = label ;
date_help = help ;
date_value = v ;
date_editable = editable ;
date_f_string = f_string ;
date_f_apply = f ;
date_expand = expand ;
}