You should update your local product inventory feed daily.
- Quarterly
- Monthly
- Weekly
- Daily
The correct answer is: Daily
Explanation: For the best user experience and accurate representation of in-store availability and pricing, it’s essential to upload your local products inventory feed at least once a day. While daily updates are the minimum, the flexibility exists to submit updates multiple times a day for specific segments of your inventory.
Read more here: https://support.google.com/merchants/answer/7371791