More Awesome Than You!

   Lately, i'm having a problem with my Elders and their Life Bars (Days Remaining) fluctuating around.  It's most noticible when 6 PM rolls around or i leave/return to the lot.  Their days remaining will show as 3 or 4 left then it jumps to 1 or it fills, or the reverse.  I don't have PETs but i have all the updated hacks.  I first started noticing it when i would do the Re-randomizer thingie in preparation for births.  Could doing that too often cause problems?  I have gotten in the habit of doing it before each birth.   I don't have SimPe so i know of no-way of checking for their exact days remaining.
   Is there anyone else who is also seeing wierd stuff with their Elders Life Bars?  Their ages don't fluctuate, just the time remaining.
   My most recent case, is a CAS couple, age of 74, their bars should have filled up when they hit 75, yet at 6 PM, their bars opened up showing 3 or 4 days, then at 8 PM that very same night, the female died of old age on me.  I'm aware there can be times where they can live beyond a full life bar. 
   It's making it difficult to predict when they will pass on, and have the toddlers/children prepared for it.

That is normal. Elders get extra days if in good aspiration, lose days if things go bad. Death by age is not an exact science.

I agree with Jordi, this is normal and has been occurring ever since the base game.  Major events like a spouse dying or a promotion can affect the days left for elders.  If you want to know for sure when your elder will die, you can check the days left in SimPE (should be 0 on the day they will die) or use Inge's days-left shrub, which does the same thing in-game.