The DateDiff tool ( introduced in commit b028e6b0a7e29614cd68bf69aff5e82988909f02 ) used to calculate the age from the difference of years from now to the birthDate is buggy. It does not take into account the number of months/days ellapsed.
To fix that, we probably need moment.js diff's method - https://momentjs.com/docs/#/displaying/difference/
The DateDiff tool ( introduced in commit b028e6b0a7e29614cd68bf69aff5e82988909f02 ) used to calculate the age from the difference of years from now to the birthDate is buggy. It does not take into account the number of months/days ellapsed. To fix that, we probably need moment.js diff's method - https://momentjs.com/docs/#/displaying/difference/
See also https://stackoverflow.com/questions/8152426/how-can-i-calculate-the-number-of-years-between-two-dates
Other option: After diffing the year, you may just compare MMDD >= MMDD. If false, remove 1 year from the age.