What impact when re-active license at 30/05 and after manual change time to 28/05

So, it is important to understand what license (re)activation does any WHY it is important I think. What this does is update the various subscription/service conrtact etc dates on the BIG-IP unit to be at parity with what F5 Support has on file. This changes of course when you want to add a new module, or even if you extend your terms of service with F5. That said, what is updated is the last valid date. So when this is updated, it is embedded in the license and is NOT impacted by changing the time... unless you change to a time in the future, after those dates have expired.

Now there are 2 impacts....
- If you do not (re)activate license, and try to install BIG-IP softare (via upgrade) which is newer than those expiration / validity dates, then serviecs will not start and configuration will not load. Outage.
- When you (re)activate, the services restart and there is a loss of service. So always suggest performing this on the standby unit, failing over, and finishing up the same (re)activation process on the last unit of the High Availability group. Avoid performing this on the ACTIVE unit.