Do leases last for 24 hours or just until end of month?

[pocketbookbrando]

I leased a very long range plane for way too much and there's no way I'll get the money back from the lease.  Should I wait 24 hours before canceling the lease or should I just dump it before the end of the month?

[pseudoswede]

Dump it on the 24th. Might as well make some of the money back flying it until you need to return it.