I’m curious about what your desired in product looks like.
If you’re trying to sort records based on when they were created, you actually don’t need another field to do this.
To sort records by a date/time value, start by creating a sorting layer on the Created Time field (or any date/time field).
Earliest to Latest
Sorting by 1 → 9 will sort date values by earliest to latest as seen in the images below.
Latest to Earliest
Conversely, sorting 9 → 1 will sort date values by latest to earliest.
Let me know if I’m misunderstanding what you’re trying to achieve, or if you have any additional questions!