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

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.

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.