when did patient 25997 first have an intake, on 06/28/2100?
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 = 25997 ) ) and strftime('%y-%m-%d',inputevents_cv.charttime) = '2100-06-28' order by inputevents_cv.charttime asc limit 1