Curiosity question, what calculation is happening here?

[lefecious]

If a cell is formatted to "general" and you type in 12-4, then hit enter, the cell changes to "4-Dec". Makes sense, but I don't want the date, I just want to show "12-4"

So I go change the format for the cell to "number" and then I type in 12-4, hit enter, and it changes to "43438.00"

What the heck is going on there?

I did finally format the cell to "text" so it would show "12-4" like I wanted it to, but now I'm just curious about the above, how it arrived at 43438.00 when I type in 12-4 if the cell is formatted as "number." I don't get what kind of calculation is taking place there and how it's leading to that result.

 

[mikerickson]

Excel is over-helpfully interpreting 12-4 as a date.
To get it to read it as as a string, type a ' first, it won't show in the cell.

type:
'12-4

 

[Eric W]

Keep in mind that Excel stores dates as numbers. 1/1/1900 was 1, 1/2/1900 (Jan. 2, 1900) was 2, and so on. This makes 12/4/2018 = 43438, or 43438 days since 1/1/1900. You usually don't see these numbers, since Excel formats dates into something more readable. But when you entered 12-4, Excel thought it was a date and internally stored it as 43438, but formatted it as 4-Dec. But when you changed the format, you see the number.

 

[lefecious]

Thanks guys! Makes perfect sense.