Automatically Formatting to Date upon Closure

[Tidr0001]

Simple but frustrating.

I have found that periodically Excel is automatically reformatting everything in large workbooks to Date Format. Initially I save these workbooks with General, Number, Currency, Text, and Date formatting within the cells. Upon opening at a later time, everything is converted to Date Format.

 

[Joe4]

I can think a few possible causes for this:
1. The file is not being saved to an Excel format, but something else, like a CSV or another kind of text or database file.
2. There is some VBA code (macros) which run automatically upon opening the files.
3. The workbook contains linked data (so it is pulling data from somewhere outside the workbook).

Do you have any of these situations?

If not, please provide more details, maybe exactly the steps that you are doing, what version of Excel you are using, and how you are saving the file.

 

[Tidr0001]

I can think a few possible causes for this:
1. The file is not being saved to an Excel format, but something else, like a CSV or another kind of text or database file.
2. There is some VBA code (macros) which run automatically upon opening the files.
3. The workbook contains linked data (so it is pulling data from somewhere outside the workbook).

Do you have any of these situations?

If not, please provide more details, maybe exactly the steps that you are doing, what version of Excel you are using, and how you are saving the file.

1. The file is not being saved to an Excel format, but something else, like a CSV or another kind of text or database file.
Majority of my workbooks are xlsx.

2. There is some VBA code (macros) which run automatically upon opening the files.
For security, Macros automatically get block until I enable. These workbooks do not have any VBA in them.

3. The workbook contains linked data (so it is pulling data from somewhere outside the workbook).
No linked data. I created the file. And again, Macros and links are automatically block until I enable.

I am using 2007. Typically saving via the menu and then closing. I am concerned the size of the files or the amount of cumputation is causing the issue.

Files are around 85 mb with around 7.5 million calculations, index / match, and if statements.
Already slimmed aout the file as much as possible.

 

[Joe4]

The file is not being saved to an Excel format, but something else, like a CSV or another kind of text or database file.

There's your problem right there! Text files (like CSV) do NOT save any formatting, just strictly text.
So every time you re-open a CSV file in Excel, no formatting is brought in so Excel goes back to its default, based on what it thinks the type of data it is.