power failure proof

[WMADKOUR]

i need to make a response to be activated on a certain date, but i face the problem of power failure, when power failed as well as battery discarged the time reset,my Question is ?  is there is any way to make a response triggered on predefined date by something not effected by power failure or is there is any way to restore last date on power failure restore ?
and is there is any way that  power failure do not reset Timers or counters or flags?

[ident]

Power failure wil battery discharged will reset all counters and other registers and date and time (but will not affect the program or configuration)

Perhaps you need a larger battery or more batteries to back up the system