When does my spouse extension start if I apply early in Thailand?

The user inquires about the start date of a spouse extension if applied for early, referencing a past experience of switching from a retirement extension. Commenters clarify that the previous change to the spouse extension started on the application date rather than the expiration date of the retirement extension. However, for subsequent yearly extensions based on marriage, applying early allows the new extension to be added to the current expiration date without losing time.