The problem is, for example on the first record, I need the value of nextPeriodTime to be "2020-04-21 12:00:00" instead of "17" (plus, I didn't quite understand why "17" ?) because
_time is after 11:00 and before 12:00, so the next period time from _time will be 12:00.
Is it possible / does it make sense to enrich the mvfilter() part to achieve something like
mvfilter(match('<<FIELD>>',"Y") AND (_time > previous-'<<MATCHSTR>>' AND _time < next-'<<MATCHSTR>>') )