In Numbers can you auto-populate a cell with a date when another cell is populated?

Question

I'm an avid Excel user and recently I've had to figure out how to use Numbers. So far I've been able to replicate all the Excel functionality that I use in Numbers... except for one thing.

In Excel I can add the following formula...

=IF(A1="", "", IF(B1="", NOW(), B1))

This formula says when a value in added to cell A1 populate cell B1 with the current date. To get this to work you must turn on an Excel feature named iterative calculation (Options==>Formulas==>Enable iterative calculation).

I use this when I'm building an Excel task journal and I want to auto-populate the date.

The important thing about this formula is that the date value is not updated another change is made.

How can I do this in Numbers? How can I auto populate a date value in column "B" when a value is set in column "A"? It's important to keep in mind that once the date is set I don't want it to change.

Here is my attempt at translating this formula in Numbers...

=IF(A2="", "", IF(B2="", NOW(), B2))

I get an error message in Numbers...

This formula can't reference its own cell, or depend on another formula that references this cell.

Thanks

Answer 1

I offer this answer only because at least it provides a workaround, albeit a slightly manual one.

Assuming that B1 is the cell that needs to have the date and time auto-populated when cell A1 is filled in, enter this formula in cell B1:

IF(ISBLANK($A1),"",NOW())

Now, when the time comes that cell A1 is filled in, cell B1 will auto-populate with the date and time.

However, to prevent cell B1 from updating if/when cell A1 is edited again, you now need to do as follows:

1. After B1 is populated, select cell B1
2. Use commandC (or go to Edit > Copy) to copy the cell
3. Use shiftcommandV (or go to Edit > Paste Formula Results)
4. Now the formula in cell B1 is replaced with the calculated value only, thereby meaning it will no longer calculate in future

NOTES:

In case this is useful for anyone else trying to come up with an answer, I also thought of:

• using an AppleScript script to replicate the above, but then realised that using a script would be no quicker that just using the Copy/Paste functionality within Numbers.

• creating an Automator service and then allocating a keyboard shortcut to that, but that too would be no quicker as you'd still need to select the cell, so using the built-in shiftcommandV shortcut is no slower than using a customisable shortcut.

Regardless, someone more adept at AppleScript may think of a more elegant solution that works with Numbers to achieve the OP's goal.

Answer 2

Unfortunately, even if you were able to reference your own cell in Numbers, there is no assignment operator.

Meaning that there would be no way to override the current value of the cell.