Have you ever forgotten about someone's birthday?

Have you remembered about it in the morning but forgot to call during the day?

Have you ever turned off a calendar notification about someone's birthday and didn't call him?

If any of these happened to you this is the right system for you.

DateReminder will email you and will keep sending emails every hour until you mark it as done

It is completely free. Just create an account, define your essential dates and never forget about them.