March 2022 - last edited April 2022
Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Rarely (0% - 9%)
What is your current game version number? 1.85.203.1030
What expansions, game packs, and stuff packs do you have installed? All except Journey to Batuu, My Wedding Stories, Laundry Day Stuff Pack, Spooky Stuff Pack, and the kits.
Steps: How can we find the bug ourselves? 1. Have a young adult/adult/elder vampire or age up an adult to an elder. 2. Make sure lifespan is either short, normal, or long.
What happens when the bug occurs? Elders and vampires have a birthday on the calendar.
What do you expect to see? No birthdays should be listed for elders and vampires.
Have you installed any customization with the game, e.g. Custom Content or Mods? Not now. I've removed them.
Did this issue appear after a specific patch or change you made to your system? Neutral/Not Sure
Read and look at the pictures below.
I am currently playing the short lifespan legacy challenge and just aged up Ukupanipo Hekekia, the mermaid sim from Island Living, into an elder. Usually, in the Simology tab, it only lists how many days a sim has lived its entire life. However, looking into the calendar I've noticed that his birthday is listed. I don't remember elder sims having their birthdays listed at all since the game doesn't really tell you how days are left until they die (unless you got MC Command Center).
Update: I went into CAS (via testing cheats + shift-clicking) to change Ukupanipo's beard and eyebrow colour to grey and right after, his birthday in the calendar disappeared. It seems like this may be a rare bug so chances are that you may not encounter it.
Vampires seem to also have their birthdays listed as well. Very rarely, of course. I edited the report and posted some screenshots below. The vampire is a young adult (you'll see it in CAS).
April 2022
I've seen this, though not super recently. I think around the time they made the calendar base game is when I first noticed it. I don't have IL, so I don't think it's a mermaids thing. I also found it disappeared pretty quickly, i.e. it would only be there if you checked pretty soon after the sim aged up into an elder.