Not if the one asked to do that calculation hasn’t had their birthday yet this year (in which case “current year - birth year” doesn’t yield age in years) or th

Not if the one asked to do that calculation hasn’t had their birthday yet this year (in which case “current year - birth year” doesn’t yield age in years) or their birth year was over 99 years ago (in which case adding “current year - birth year” overflows into the partner’s age)