When you bring a .txt file into Excel, Excel reads the date file and converts four-digit years (e.g., 1998) to two-digit year format (e.g., 98). You can prevent this.
When you open an Excel file saved as text, the Text Import Wizard lets you make some format choices.
- Click through the several screens (clicking on the Next button).
- On the third and final screen in the Data Preview area, select the Date column.
- In the "Column data format" area, choose Text
- Click on Finish
Another approach is to save the file first as an Excel spreadsheet or worksheet with the four-digit year properly formatted. Then save the .txt file under a different name.
When you need to make changes, open the Excel file, not the .txt file. Make your changes and save again in both formats.
If four-digit years were displayed on the screen, then the tab delimited text file will have four-digit years.