when did patient 23070 last take an intake on this month/04?
select inputevents_cv.charttime from inputevents_cv where inputevents_cv.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 23070 ) ) and datetime(inputevents_cv.charttime,'start of month') = datetime(current_time,'start of month','-0 month') and strftime('%d',inputevents_cv.charttime) = '04' order by inputevents_cv.charttime desc limit 1