ATM if you want to look at your combat log at a historical day or month (say Jan 2020), you have to click the arrow on the bottom right corner hundreds of times. it would be great if the search function allowed you to narrow your combat log to a particular month. or make the combat log more user-friendly and give us more options when looking up our kills and losses (kills by system, kills by ship class etc).
Try searching through the actual game files on your computer.
Alt+R and type: