To change date formats in Excel using the LEFT, RIGHT, and MID functions, you can extract different parts of a date (like day, month, and year) as text and then rearrange them as desired. Here’s a step-by-step guide:

 1. Understanding the Functions

   - LEFT(text, [num_chars]): Extracts a specified number of characters from the start of a text string.
   - RIGHT(text, [num_chars]): Extracts a specified number of characters from the end of a text string.
   - MID(text, start_num, num_chars): Extracts a specific number of characters from the middle of a text string, starting at the specified position.

 2. Example Scenario

Let's say your date is in the format `YYYY-MM-DD` in cell A1 (e.g., 2023-08-15), and you want to convert it to `DD/MM/YYYY`.

 3. Using the Functions

   - Extract the Year (YYYY): Use the `LEFT` function.
     =LEFT(A1, 4) 
     This will return 2023.

   - Extract the Month (MM): Use the `MID` function.
    
     =MID(A1, 6, 2)
     
     This starts from the 6th character and takes the next 2 characters, returning 08.

   - Extract the Day (DD): Use the `RIGHT` function.
     =RIGHT(A1, 2)
     This will return 15.

 4. Combine the Parts in Desired Format

To put it all together in `DD/MM/YYYY` format, use the `&` operator to concatenate the parts with `/` in between:
=RIGHT(A1, 2) & "/" & MID(A1, 6, 2) & "/" & LEFT(A1, 4)

This formula will return 15/08/2023.

 5. Adjustments for Other Date Formats

If your date is in a different format, adjust the numbers in the `LEFT`, `RIGHT`, and `MID` functions to match the positions of day, month, and year.

This approach is especially useful when Excel doesn’t recognize the date format as a true date value, allowing you to reformat it using text functions.