How do I automatically Split data as new rows are added to the sheet?

I am trying to automatically split a date stamp that comes into my spread sheet via IFTTT. I have the formula to SPLIT the data worked out and pointing to the next blank cell, but as the new date stamp comes in it overwrites the blank row and deletes the SPLIT formula for that row. I am at a loss as to how to correct this. Here is the function I am using =iferror(SPLIT(A:A, "at", false)).
Any ideas?