It may be a sign of old age but, I’m struggling more and more to remember how old people are. I have addressed this by having a review of my Google contact data and making sure, where I know someone’s birthday I have recorded it there.
This has the added advantage of creating a Google calendar showing me their birthdays.
I have now created a script which scans my contacts to find their birthdays, does some arithmetic to work out their age and store this in a custom field. I have set up a trigger to run this once a week.
Here is the script that I created: