You're correct - exact date no, but the exact date must not be exceeded.
So, for example, if the exact date now falls on a Sunday, it would be advisable to go on the Friday before at the latest, as going on Monday may land them in hot water.
Or, as this thread has been discussing, if the date has been reset because of an earlier visit within the last 12 months.

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Fighting or Accepting - its difficult to know which is right and when.

Yes I thought it was the case you could go early but not exceed the date.

In terms of my registration I decided to get written clarification from my officer. I got two emails which confirm that the date has deffo changed and been reset. 

Email 1:

Good morning Mark
 
I’m well thank you.
 
I hope you are well also.
 
Yes, your next registration date will be 20/10/2021 or later if you attend the Police Station sooner to register any changes. If the Pros.160 form is completed on your attendance your annual date will automatically reset to 12 months from the date it was completed.
 
Regards

Email 2: (I asked a question as thought the above didn't answer everything I originally asked) 

No Mark, your attendance the other month will be fine and will stand as your new annual attendance date. No need to  attend this week.
 
Given the current Covid-19 situation it isn’t advised to make any unnecessary trips anyway.
 
Thanks for your enquiry though.

Just on the back of that too. I coincidently had the main team contact me yesterday because their contact details changed.

Because I’m a worrier I thought I’d ask the woman on the phone for reassurance and she confirmed the same as what my allocated officer had confirmed in the email.

Just for reference for anyone else.

Hoping this posts as I don't seem to be able to start a new thread.

Thought I would add it to my existing one.

I know that I need to report my new debit card within three days of today, as it has just arrived. 

The bit that concerns me is the card states valid from 12/20, and the attached letter has no date on, so im worried they will think it was issued last month. 

I assume your debit card came in the post attached (glued) to a letter?
If so does the letter its self provide a date?
If you have already given bank account details as well as previous debit card information I don't think you have anything to worry about. But if in doubt see if you can speak to your PPU.

Yes it came glued.

I’ve looked everywhere on the letter and there’s no date.

I have reported my bank account and debit card details previously, this debit card will be the new card as the previous one is expiring this month.

I do have a text from the bank saying expect your new card in five working days, think that will suffice if I’m asked?

It’s worth a quick call to tell your ppu it came today. As long as you’re showing you’re playing by their rules, it should be fine.

They may even take registration of it over the phone since we’re in lockdown. Main point is don’t worry

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Fighting or Accepting - its difficult to know which is right and when.