Often we hear word of mouth that it's someone's birthday coming up but don't have specific year and we're even lucky to have the date of the month. There are many cultivating opportunities and auto-generated tasks that can be taken advantage of if we happen to only know the month or month/day and not the year. In fact, there are times that we are speaking with someone and we happen to hear how old they are, so we could easily do the math and record just the year and have some demographic information to work from.