Here’s a fun trick to try with Excel. You can make a list of friends or colleagues and create a birthday reminder. Here’s how to do it.
First, you’ll need to create a worksheet and input the names and birthdates of friends or colleagues. Use any date format you prefer.

Next, enter or copy this formula into the cell:
=IF(MONTH(C3)<>MONTH(TODAY()),” “,IF(DAY(C3)<>DAY(TODAY()),” “,”Happy Birthday”))
C3 is the cell which contains the birthday date, you can change it as you need) into a blank cell D3, for example.

Press the Enter key, then select the cell D3 and drag the fill the handle to the range where you want to apply this formula. When the birthday date arrives it will show a message Happy Birthday in the cell. An Example: If the date is October 8 today, it will show Happy Birthday to Ritika.

~ Jiten Chaturvedi
A lot of work to set up a reminder schedule for birthdays, anniversaries, and other important events.
Why not just use either of the following FREE software which is so easy to use and gives you multiple ways to be notified in advance when an important date is coming:
punchbowl.com or
birthday-reminders.com
These are the 2 I use and they work perfectly.
There are many other that work similarly and are totally free.
Hello. And Bye.