You need to write a "System > Script > +" named "Reset" with the line:
/ip firewall filter reset-counters-all
OR
/ip firewall filter reset-counters
in it.
Then do a "System > Scheduler > +" name it "ResetCounters", on-event put "Reset", your desired daily start-time, and VERY IMPORTANT change Interval to "1d 00:00:00" or copy paste the following in "New Terminal" window:
/system scheduler
add interval=1d name="ResetCounters" on-event="Reset" policy=reboot,read,write,test,romon start-date=\
jan/14/2019 start-time=00:30:00
This will reset your counters every day at the specified time so only the daily stats are shown.