Create a table of time series data

create table time_data as  
select * from (   
  select date'2022-08-01'   
           + numtodsinterval ( level , 'minute' )   
           + ( mod ( level, 17 ) / 60 / 24 )  
           + ( sin ( level ) / 24 ) datetime  
  from   dual  
  connect by level <= 200  
  union  all  
  select date'2022-08-02'  
           + ( level / 4 )  
           + ( sin ( level ) / 24 ) datetime  
  from   dual  
  connect by level <= 100  
  
)  
where  datetime >= date'2022-08-01'  
and    datetime not between date'2022-08-01' + 15/24/60 and date'2022-08-01' + 19/24/60   
order  by datetime 

alter session set nls_date_format = 'DD-MON-YYYY HH24:MI'

Group rows in 5-minute intervals

with rws as (   
  select trunc ( datetime ) dy,   
         trunc ( datetime, 'mi' ) mins,   
         5 / 1440 time_interval   
  from   time_data   
), intervals as (   
  select dy + (   
           floor ( ( mins - dy ) / time_interval ) * time_interval   
         ) start_datetime   
  from   rws   
)   
  select start_datetime, count(*) from intervals   
  group  by start_datetime   
  order  by start_datetime   
  fetch first 5 rows only

Group rows in 10-minute intervals

select trunc ( datetime ) + (   
         floor (    
           ( trunc ( datetime, 'mi' ) - trunc ( datetime ) )    
             * 1440 / 10    
         ) * 10 / 1440   
       ) start_datetime,   
       count (*)   
from   time_data   
group  by trunc ( datetime )    
            + ( floor (    
                  ( trunc ( datetime, 'mi' ) - trunc ( datetime ) )    
                    * 1440 / 10    
                ) * 10 / 1440    
            )   
order  by start_datetime   
fetch  first 5 rows only

Group rows in N-minute intervals

declare   
  duration_in_minutes integer := 5;   
begin   
  for rws in (    
    with rws as (   
      select trunc ( datetime ) dy,   
             trunc ( datetime, 'mi' ) mins,   
             duration_in_minutes / 1440 time_interval   
      from   time_data   
    ), intervals as (   
      select dy + (   
               floor ( ( mins - dy ) / time_interval ) * time_interval   
             ) start_datetime   
      from   rws   
    )   
      select start_datetime, count(*) row#    
      from   intervals   
      group  by start_datetime   
      order  by start_datetime   
      fetch  first 5 rows only    
  ) loop   
    dbms_output.put_line ( rws.start_datetime || ' - ' || rws.row# );   
  end loop;   
end; 

Group rows in 5-minute intervals including missing times

declare   
  duration_in_minutes integer := 5;   
  start_time          varchar2(20) := '01-AUG-2022 00:00';   
  number_of_intervals integer := 12;   
begin   
  for rws in (    
    with times as (   
      select to_date ( start_time, 'DD-MON-YYYY HH24:MI' )   
               + ( ( level - 1 ) * duration_in_minutes / 1440 ) dt   
      from   dual   
      connect by level <= number_of_intervals   
    ), intervals as (   
      select dt start_date,   
             dt + ( duration_in_minutes / 1440 ) end_date   
      from   times   
    )   
      select start_date, end_date, count ( datetime ) row#   
      from   intervals i   
      left  join time_data t   
      on     start_date <= datetime   
      and    datetime < end_date   
      group  by start_date, end_date   
      order  by start_date   
      fetch  first 5 rows only   
  ) loop   
    dbms_output.put_line ( rws.start_date || ' - ' || rws.row# );   
  end loop;   
end; 

Group rows in N-minute intervals starting from source data

declare   
  duration_in_minutes integer := 5;   
  number_of_intervals integer := 12;   
begin   
  for rws in (    
    with start_date as (   
      select min ( datetime ) start_date,   
             duration_in_minutes / 1440 time_interval   
      from   time_data   
    ), intervals as (   
      select start_date + ( ( level - 1 ) * time_interval ) start_date,   
             start_date + ( ( level ) * time_interval ) end_date   
      from   start_date   
      connect by level <= number_of_intervals   
    )   
      select start_date, count ( datetime ) row#   
      from   intervals   
      left  join time_data   
      on     start_date <= datetime   
      and    datetime < end_date   
      group  by start_date   
      order  by start_date   
  ) loop   
    dbms_output.put_line ( rws.start_date || ' - ' || rws.row# );   
  end loop;   
end; 

Group rows in N-minute intervals with variable gaps

declare   
  duration_in_minutes integer := 5;   
begin   
  for rws in (    
    select *   
    from   time_data   
      match_recognize (   
        order by datetime   
        measures   
          init.datetime as interval_start,   
          init.datetime   
            + numtodsinterval ( duration_in_minutes, 'minute' ) as interval_end,   
          count(*) as row#   
        pattern ( init time_interval* )   
        define   
          time_interval as datetime <   
            init.datetime + numtodsinterval ( duration_in_minutes, 'minute' )   
      )   
    fetch  first 5 rows only   
  ) loop   
    dbms_output.put_line ( rws.interval_start || ' - ' || rws.row# );   
  end loop;   
end; 

Combine all rows within N-minutes of the previous row

declare   
  duration_in_minutes integer := 5;   
begin   
  for rws in (    
    select *   
    from   time_data   
      match_recognize (   
        order by datetime   
        measures   
          init.datetime as interval_start,   
          init.datetime   
            + numtodsinterval ( duration_in_minutes, 'minute' ) as interval_end,   
          count(*) as row#   
        pattern ( init time_interval* )   
        define   
          time_interval as datetime <   
            prev ( datetime ) + numtodsinterval ( duration_in_minutes, 'minute' )   
      )   
    fetch  first 5 rows only   
  ) loop   
    dbms_output.put_line ( rws.interval_start || ' - ' || rws.row# );   
  end loop;   
end;