Since The Sims 3 is the only game so far that gave us the freedom to set the length of any lifestages as we wish, I wonder what the different settings of you players are. If you have Pets installed include your settings for dogs, cats and horses. And if you also have Seasons and/or Supernatural, you may also write your settings for seasons length and moon cycle. You may also add your commentary as to why you chose these settings.

My settings are this:
Sim:
Baby 2, Toddler 5, Child 30, Teen 40, Young Adult 60, Adult 60, Elder 50
Dog:
Puppy 20, Adult 54, Elder 30
Cat:
Kitten 20, Adult 60, Elder 36
Horse:
Foal 20, Adult 75, Elder 36

My lunar cycle is on 8 days.

My seasons are usually on 5 days each with 20 days per year. However, if I play in hot environment, I shorten winter to 3 days and lengthen summer to 7 day and vice versa for cold environment, where I shorten summer to 3 days and lengthen winter to 7 days, always keeping the 20 days year.

This setting works well for me. I am quite used to 5 days seasons from Sims 2, so I kept them in Sims 3 as well. Plus that way, the holidays will always fall on different day, not the same as with the default 7 days settings, which adds to my gameplay diversity. Lifespan settings are set so the kids will experience every season at least once and the rest is set to be at least slightly realistically longer to the child lifespan. Toddlers and babies are shorter, because, quite honestly, babies are no fun in Sims 2 and toddlers on 5 days span are quite challenging to be taught at least the basic skills, not to mention anything beyond them and I like that challenge. Besides, babies and toddlers don't have any real interaction with the environment, so it doesn't matter to me if they don't see every single season. The only oddity in my game is the lunar cycle settings on 8 days, which means I have 2.5 lunar cycles per year, which is quite nonsensical, but I couldn't care less. Full moon every eight days is more then enough for me

Baby: 3
Toddler: 7-10
All other lifespans on maximum. (I use a mod from NRASS to scale skill rate to life span.) Baby and toddler are not max because of boring/would drive me nuts if it were longer. I have Pets, and their lifespan is also max.

Lunar cycle: 10. Seasons: 13 days each. This way, the holidays don't occur on the same days of the week, and the lunar phase doesn't change at the same frequency as the season.

I have Supernatural (and Pets), I tend to leave lunar cycle at 10, and change the lifespans at the start of each new save I start. It is fairly common for me to have long lifespans for each stage and age them up when they have learned or achieved what I want them to at that age-span level. It seems to happen well before they would age up normally.

If I'm playing the game with my hand crafted, individually designed sims, I set the lifespan to long. Dang if they're all gonna die/get old on me before I get to interact with them.
If I'm playing with NRAAS SP + Population, then I set it to short, cuz the graveyard needs residents and I don't care about a well balanced but randomly generated population of sims.
Pets? No, I can't stand it when my pet dies. I can feed sims to cowplants all day, or play a hit man (my latest game) but losing my sim dog... too sad for me. Not why I play games. I only have Pets installed so I can load Custom Content with pets. I hate having parrots all over the ground. Parrots everywhere. You'd think there would be separate pet spawners, but NOOOoooo... EA got a little Lazy and hijacked other spawners. I'm thinking of uninstalling pets, but I have a Steam version and it didn't react well to the last time I tried uninstalling pets.
Pets has nice clothes, tho.

I usually put my settings on long, but change the infant stage to the lowest amount of days possible, toddler to 7 days, teen and children to 14 days, young adults at 84 days, adults at 42 days , and elders at 35 days. I keep them at multiples of 7 so they age up on the same day of the week each time.. (idk why though haha)

My current lifespan.


I also recently changed the lifespan for large birds and hopefully I did that right. I'll get around to changing the other minor pets too.
0=25,566
1=25,569

Well, I'm not playing currently, but when I did, I used a slightly modified Long setting (Toddler stage 10 days, down from 15, Child stage 20 days, up from 15, and everything else at their defaults). Seasons would be 7 days long (considering changing that if I ever play again), and the lunar cycle 8 days long.

Baby 2, Toddler 5, Child 9, Teen 15, Young Adult 22, Adult 22, Elder 15. I don't like how toddlers have the same days as children and I think babies would be easier with one less day. I don't really like elders, so I took two days off and gave it to the YA and adult stages. Total is still 90 days. Lunar cycle is default.

I use the standard ones. They are fine for me.

mostly "rule of 4" (4 days==1year) which is somewhat kinda "natural" according to standard pregnancy lenght. So:
baby: 4days (one year)
toddler: 12 days (up to 4)
kid: 24 days (up to 10)
teen: 32 (10 to 18) though I have two separated castes, as long as I remember to update of course - "small teens" 10-15 and "teens" 15-18 with separate schools and different scenarios, for example "small teens" mostly rather make mess, rebel, prank etc. than dating and such stuff, exceptions are rare, while older (depending of personality - it actually works a bit better in Sims 2) gets into more mature activity like teen work, clubs of interests, partying, studying hard (or not at all), dating etc. I also use Consorts' grow for kids and teens and Consorts' Age for adults.
ya: 48 (19-30) pretty standard I suppouse, if sim goes into college I add 2 years (8 days) to his/hers age per each trip
adults: 116 (31-60)
elders: minimum 10, random

obviously it is completely out of touch with seasons, demands lowering skill aquisition rate, work efficiency etc.

I've tried week==year and moth==year spans but never really had time to play that way.

I do one day = one year. It doesn't work in a lot of ways but I would lose interest really quickly if I tried to make it longer.

Baby: 3 days
Toddler: 4 days (so starts at age 3)
Child: 6 days (so starts at age 7)
Teen: 6 days (starts age 13)
Young Adult: 26 days (starts at age 19)
Adult: 25 days (starts at age 45)
Elder: 20 days (starts at age 65)

I've got a 60 days= a year because my seasons are 15 days each.
Sims:
Pregnancies =30 days
Babies =appox 60 days (up to about first birthday.)
Toddlers -appox 120 days(1-3 years old)
Children =appox six simyears or 360 days.(3-9 years old)
Teens =appox 180 days or three years.(9-12 years)
Young Adults =approx 540 days or 9 years(12-21years)
Adults =approx 1080 days or 18 years(21-39+ years)
Elders =approx 540 days or atleast 9 years(39-48+ years)
It's based on lifespans in the 16th or 17th centuries.

Emmet Brown: I also have a Steam version. To uninstall, simply untick the dlc, and then go into your registry and find the registry file of the dlc and delete it. There’s a more complicated guide on the steam forums, there you can find the path of the registry file.

Sim (124 days)
Baby -2 Toddler - 5 Child - 12 Teen - 21 YA - 28 Adult - 30 Elder - 24+

It's loosely based on the 1 year = 1 day rule but some Elder Sims overdo it and live to 177 days. When the town has too many Elders, I think Nraas SP helps to cull down the Elder population and it once happened to have so many Elder Sims drop dead on a single day.

I rarely use Pets but I use these lifespans (4 days puppy / kitten; 7 day foal; 7 days elder)
Cat - 49 days
Dog - 56 days (idk, I'm a dog person)
Horse - 63 days

As for Seasons, I use a 7 day cycle and the Festival is always set at Sunday. The Lunar Cycle is left as it is on default.

Mine are set long, really really long. Not as long as Deshong's but about 1/3 of that.

Year- 120 days
Each season- 30 days
Lunar phase- 10 days

Sims- 9,600 days (80 years)
All pets- 1,800 days (15 years)

I have them all set according to that for each age stage, but I as my computer died I can't check the exact days for each although it is a similar set up to Deshong's.