Welcome to the Airtable community!
As much as Airtable looks like a spreadsheet, it is not a spreadsheet, and cannot do some things that come easily in a spreadsheet. This is one of those things. Records in Airtable are not aware of which record comes “before” or “next” because the order of records is not fixed.
In the user interface you can use the drag handle on the date field to fill in increasing dates. Just select multiple cells with increasing dates before you begin the drag.
You can also use a scripting automation to calculate the next date and fill it in. However, this may be overkill for your situation a d too slow.
