How To Get Daily Max (Value) Query

I am looking to get the maximum value for every 24 hour period for a month. So for example my date range can be defined by...

select to_date('&date','mm yyyy')-1 + level as DateRange
from dual
connect by level <= '&days'

...where I can provide the first date of the month and number of days in the month or a lesser value if less time is required. So, the results of the above query plus 24 for the range. I thought a some Googling would provide me what I needed, but my search came up empty.

I was hoping to do something like this...

select utctime, max(value) from table where utctime between.