If you ask Siri how old you are, there is a decent chance that the voice assistant will get your age wrong if your birthday has yet to pass this year.
For example, while my birthday is in April and I am still 27 years old for a few more months, Siri tells me that I am already 28 when asked. As noted by the Dutch blog iCulture, the discrepancy likely relates to Siri miscalculating birthdays by only taking into account a person's year of birth and not the month or day. As evidence of this, Siri displays the correct age for anyone with a birthday that has already passed this year.
Note that if Siri doesn't know your age, then you probably haven't added your birthday to your iPhone's contact card.
While you probably know your own age, the issue extends to the ages of anyone in your iPhone's contacts list that you have entered a birthday for. Siri tells me that my wife is 29 years old, for example, when she is actually 28.
We asked a handful of iPhone users on both iOS 15.3 and the iOS 15.4 beta to ask Siri how old they are, and all but one said the wrong age appeared. It's possible that the issue doesn't affect all users for reasons unclear.
All in all, this is a minor issue, but it certainly doesn't help with Siri's reputation. Fortunately, it should be something that Apple can fix quite easily.
Update - February 1: Apple appears to have resolved this issue with a server-side fix.
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