To convert an integer value of seconds past midnight into a time value in Excel, use the following formula:

Here's a step-by-step guide on how to use this formula:

1. Open a new or existing Excel worksheet.
2. Enter the integer value of seconds past midnight in a cell (let's say it's in cell A1).
3. In another cell, enter the formula
   Formula:

   =TIME(0,0,A1) 

   .
4. Press Enter to see the result.

The TIME function takes three arguments: hours, minutes, and seconds. Since we only have the number of seconds past midnight, we can set the hours and minutes to zero and use the integer value of seconds as the third argument.

The result will be a time value that you can format as desired (e.g. 2:45 PM). To do this, select the cell with the time value, right-click, and choose Format Cells. In the Format Cells dialog box, select Time and choose the desired time format.

That's it! You should now have a time value that corresponds to the integer value of seconds past midnight.