According to Google Play Help - How to change your Google Play country, the following means 12 months are needed to change one's Google Play country, because one must first create a payments profile, and then wait 12 months first. Correct?:
How to change your Google Play country
If you move to a new country you may want to change your Google Play country. Your Google Play country determines what content you see in the store. The apps, games, and other content in the Store can vary by country.
- You must wait 12 months after initially creating a payments profile before you can change your Play country. You can only change your Play country once per year. If you change your country, you won’t be able to change it back for one year.