Hi, Balram I don't think that there is send_wait method for this, but I would suggest You to use workshift_abs2work method, since this method allows you calculate difference between dates taking workshift in to account, here is usage example:
duration resol_dur;
resol_dur = workshift_abs2work("Mon - Fri { 8:00 am - 5:00 pm }", open_date, resolve_date);
there is also another function that allows calculate date, from given start date and duration it is called workshift_work2abs
workshift_work2abs("Mon - Fri { 8:00 am - 5:00 pm }", open_date, resol_dur);
Anyway your code should look like this
uuid who;
duration resol_dur;
resol_dur = workshift_abs2work("Mon - Fri { 8:00 am - 5:00 pm }", open_date, resolve_date);
send_wait(0,top_object(), "call_attr", "cnt", "current_user_id");
who=msg[0];
send_wait(0, top_object(), "call_attr", "api", "update_object_super", who, persistent_id, 0, "zresolution_time", resol_dur);