objective c - NSTimer, NSRunloop and deep sleeping mac -

i'm programming app in objective-c on mac , need help. each day, @ 23:59, app calling method generate report

nstimer *timer = [[nstimer alloc]                   initwithfiredate:endoftheday                   interval:0.0                   target:self                   selector:@selector(endday)                   userinfo:nil                   repeats:no];  [[nsrunloop currentrunloop] addtimer:timer formode: nsdefaultrunloopmode]; 

which working expected unless computer in deep sleep mode. thing : need timer call method @ exact moment of day if in sleep mode. i'd not have prevent sleep. can me?

thanks in advance!

check out iopmschedulepowerevent:

 ioreturn iopmschedulepowerevent(    cfdateref time_to_wake,    cfstringref my_id,    cfstringref type); 

note must called root.