Estimating battery life from capacity and varying load
You should calculate the mean consumption which equals to :
MEAN CURRENT (in mA)= (5x50 + 10x650 + 0.1x86385) / (5+10+86385)
Now divide the capacity on the mean consumption to get the time (assuming you can drain all the juice out of your battery which is not so true.)
To be more accurate, you should examine the discharge curve (voltage as function of time) and examine where your circuit will actually stop to function. This may be the point where:

Regulator's dropout voltage violated. The output voltage will then start to drop.
Then the microcontroller / devices on your board will reach the non-operating-conditions (check your datasheet.)