Today is the last day to check if your domain name is ready for the planned change from 1st February. According to website https://dnsflagday.net/ current DNS is unnecessarily slow and inefficient because of efforts to accommodate a few DNS systems that are not in compliance with DNS standards established two decades ago.
DNS service provider and DNS software have agreed to coordinate removing accommodations for non-compliant DNS implementations from their software or services, on or around February 1st 2019. This change will affect only sites operating non-compliant software. This change will make most DNS operations slightly more efficient, and also allow operators to deploy new functionality, including new mechanisms to protect against DDoS attacks. Test your domain name now.