TTL
- Infrastructure records (NS related): 1 – 2 days (86400 – 172800 seconds)
- Default $TTL: 1 hour – 1 day
- Minimum Zone TTL: 5 – 10 minutes
- Maximum Zone TTL: 1 – 2 days
SOA Refresh and Retry
- SOA Refresh: 1 – 4 hours
- SOA Retry: 15 – 60 minutes
SOA Expire
- SOA Expire: 1 – 3 weeks
SOA minimum
- SOA Minimum: 15 – 60 minutes
Source: https://securityblog.switch.ch/2014/02/06/zone-file-recommendations/