Adding bans trough Bans.json

How can i add bans trough that file? like i wanna ban somone for only 24 hours.
i cant because it looks coded to me

"banTime": 1545915392, like that< doesnt say anything just random code
how in the world can we edit this?
i wanna add ban after they left.


Probably in milli or micro seconds.

That number in microseconds is 25 minutes approx.