Rules for unlocking SUN is as follows

1. First distribution: 3:00–4:00 UTC on September 11, 2020
2. On September 11, 2020, SUN mined from the start of Genesis mining through September 10, 4:00 UTC will be available for withdrawal.
3. From September 11 2020, 04:00 UTC to September 16 2020, 13:00 UTC, everyday at 4:00 UTC. users will be able to withdraw the SUN tokens generated from the previous day ending at 4:00. All SUN tokens will be open for withdrawal after 13:00 UTC on September 16, 2020.

https://medium.com/@TronFoundation/notice-on-moving-up-the-withdrawal-of-sun-from-sun-genesis-mining-dbbfacedc299