Hello, I am a solicitor with over 15 years experience. I will try to help you with this.
There is nothing to do at the moment. You need to wait to hear further about this. You will have told the police your address and personal details when stopped. If any action is to be taken you will be sent details of this (eg a court summons) to that address and will need to respond to that. It is unlikely that the error in date in the traffic offence report will help you avoid conviction if a summons is issued.
If the police have not commenced proceedings within 6 months of 9th April they will be out of time.
how can they issue me with a summons for an offence committed on a date that is in the future ,on the report
The date on the report is an obvious mistake and if they issue the summons they will correct the date, even if they don't do this and issue the summons with the wrong date then the prosecutor will ask the court for permission to amend the summons which will be granted. Your best hope is that the police officer who made the mistake realises his mistake and either thinks it is a mistake which will undermine a prosecution and therefore does nothing or just decides to sit on it to hide his embarassment.