when was first time the arterial bp mean of patient 23760 was greater than 88.0 since 420 days ago?
select chartevents.charttime from chartevents where chartevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 23760 ) ) and chartevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'arterial bp mean' and d_items.linksto = 'chartevents' ) and chartevents.valuenum > 88.0 and datetime(chartevents.charttime) >= datetime(current_time,'-420 day') order by chartevents.charttime asc limit 1