Assigning a Value to cell ~ circular reference

[bensaini]

If you are familiar with languages like C, you would know the concept of assigning a value to variable. e.g a=a+23.

I want to do something similar with the value in an excel cell.

if(today's date = earnings date)

current cell value = current cell value + 23
(so cell value should now be equal to old value+23, if today's date is equal to earnings date)

can you please suggest how best could I do that without running into reference glitch. Thank you.

Ben