Pellatarrum: Mechanical Effects of the Day/Night Cycle

I've written before about the Day/Night cycle in Pellatarrum, but I feel it's time to revisit it because 1) it's been 8 years since I last talked about it and 2) now that I'm actually running games in the setting and not  just talking about it in the abstract, I've realized that there are important mechanics that I missed.

Daylight: 9 am - 3 pm
During the hours of full daylight (during which time the Death Sun is fully obscured), anything which helps life is given a +2 bonus and anything which harms it is given a -2 penalty. Examples:

• -2 to all damage rolls, including those from magic and the environment.
• Exception: damage dealt to undead does not suffer this penalty. 
• +2 to Heal checks and +2 hit points regained from both natural (including resting) and magical healing. 
• +2 to Fortitude saves and Constitution checks. 
• Exception: living creatures below 0 hit points but who have not yet died automatically stabilize during the day, no roll required. 
• Exception: undead are always considered "harmful to life" and therefore any Fortitude save or Charisma check (undead don't have Con scores) made by them during the day have a -2 penalty.
• +2 to all Positive Energy channeling that heals the living and harms or turn the undead. 
• All undead with Channel Resistance have a -2 penalty to their will saves. 
• All undead are considered dazzled when exposed to daylight (this has no effect indoors or underground). 
• Anyone who dies while exposed to full daylight, for whatever reason, will never become undead. Those who die during the day but not exposed to daylight have a decreased chance of it. (I can't recall of there's ever an effect where the DM rolls to see if someone rises as undead or not. If so, apply the penalty.)

As you can see, the day time is inimical to the undead. However, when the Life Sun sets and the Death Sun is rampant, all that switches. 

Night: 9 pm - 3 am
Conversely, during the hours of full sight (during which time the Life Sun is fully obscured), anything which harms life is given a +2 bonus and anything which helps it is given a -2 penalty. Examples:

• +2 to all damage rolls, including those from magic and the environment.
• Exception: damage dealt to undead does not gain this bonus. 
• -2 to Heal checks and -2 hit points regained from both natural (including resting) and magical healing. 
• -2 to Fortitude saves and Constitution checks 
• Exception: living creatures below 0 hit points automatically begin dying at night, no roll required. 
• Exception: undead are always considered "harmful to life" and therefore any Fortitude save or Charisma check (undead don't have Con scores) made by them during the day have a +2 bonus. 
• -2 to Channeled Positive Energy to heal the living and to harm or turn the undead. 
• All undead gain +2 Channel Resistance at night, including those who already have it. 
• Anyone who dies while exposed to the Death Sun will, barring something truly unusual, always reanimate as undead. Those who die from violence at night will almost always reanimate (sometimes within minutes or seconds after death -- take your cue from zombie movies). Those who die peacefully will probably reanimate, but at a decreased chance.  
• How quickly they reanimate, and what into, should be a GM call. Low-level characters are usually zombies, but the nature of their death should be a factor. Higher level characters usually become more powerful types -- see the post On the Elemental Nature of Undead. 

Twilight: Dawn (3 am - 9 am) and Dusk (3 pm - 9 pm)
During the hours of dawn and dusk, there are no bonuses and no penalties associated with the Life or Death Suns, as their presence in the sky cancels each other out.

GMs who desire enhanced granularity at the cost of extra bookkeeping may, if they wish, use the following schedule:

• 6 am - 9 am: +1 to life, -1 to harm
• 9 am - 3 pm: +2 to life, -2 to harm
• 3 pm - 6 pm: +1 to life, -1 to harm
• 6 pm - 9 pm: -1 to life, +1 to harm
• 9 pm - 3 am: -2 to life, +2 to harm
• 3 am - 6 am: -1 to life, +1 to harm

There's probably a sweet spot around 6 pm & 6 am where the suns are precisely equidistant and there are no penalties or bonuses, but making it last for any length of time disrupts the symmetry of the system.