Alpha Wolf Shark,
Unfortunately the current messaging can be a bit vague. Your suspension will end at the same hour of the day that it began. So if you were banned at 6 PM on Feb. 22nd, and it says it will be released on Feb. 23rd, then your suspension will end at 6 PM on Feb 23rd.
Also, to give you some context on the ban, its most likely from the automated leaver system which detected your left a game when your laptop died. I know this can sound harsh, especially since you didn't plan on your laptop dying, but due to the nature of League of Legends, constant leavers can pose a problem.
Don't worry though, the Leaver Buster system is designed to give you some leeway in case real life accidents happen. However, if you leave enough games then it will give a temporary suspension.
The bright side though is that this isn't permanent. In fact, when you return to LoL if you continue to play games without leaving then you'll earn your "grace period" back. This will let you leave a game in an emergency without being banned by the system. But careful, leave too many games again and you'll be bumped up a leaver level and left with a new suspension!