Give this a try
index=abc_core search_test=* earliest=-7d@h latest=@h
| eval date_hour=strftime(_time,"%H") | where date_hour=[| gentimes start=-1 | eval search=strftime(relative_time(now(),"-1h@h"),"%H") | table search ]
| eval day=strftime(_time,"%F")
| chart count over search_test by day
... View more