If you wish to know the day, month, and year of a date in the future or past that is x number of days from before or after today or some specified date, you can perform the calculation in spreadsheet programs such as Microsoft Excel, or the free and open-source software (FOSS) programs LibreOffice Calc and OpenOffice Calc, by placing a date in a cell and then using addition or subtraction on that date to determine the desired date. E.g., if you place
7/1/2024 for
July 1, 2024 in cell A1, you could use the formula =A1 + 280 in
cell A2, if that cell is specified with a date format (you can right-click on
the cell and choose Format Cells to verify a date format is selected
for the cell) to calcuate the date that is 280 days from July 1, 2024. You
would then see 4/7/2025 for April 7, 2025 in cell A2, if you use
the month/day/year format for the date in cell A2. Or you could put the formula
=A1 - 280 in the cell to determine the date that was 280 days
before, i.e., 9/25/2023.
