I have a formula for calculating when I can plant seeds, according to the LFD (last frost date), which is and will remain 3/29/2020. Weeks is how many weeks before the LFD I can plant the seeds. The formula:
DATEADD({LFD},-{Weeks Start},‘weeks’)
Currently I have a whole column for LFD that is set to autofill 3/29/2020 into every row, of which I have 350+. Instead of this whole column for LFD, is there a way I can somehow reference this number one time within a formula, or within one cell somewhere instead of a column of 350 rows with the same number?