what time patient 40059 got a lab test for the first time the last month?
select labevents.charttime from labevents where labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 40059 ) and datetime(labevents.charttime,'start of month') = datetime(current_time,'start of month','-1 month') order by labevents.charttime asc limit 1