Can you be outside the country when citizenship granted?

Hello,

I wanted to ask what would happen if citizenship was granted whilst you were out of the country? When it's granted I understand ILR is cancelled so will there be issues re-entering the UK?

Also the 90 days in the last year our of the country criterion. Does the clock for that stop the day you apply for citizenship?

Very grateful for any help.

I wanted to ask what would happen if citizenship was granted whilst you were out of the country? When it's granted I understand ILR is cancelled so will there be issues re-entering the UK?

You won't be granted citizenship until you attend your ceremony and swear your allegiance and make your pledge. You are given your cetificate of citizenship at your ceremony. 
https://www.gov.uk/citizenship-ceremonies

Your ILR is gone as soon as you become a British citizen. You need to return your BRP within 5 days to avoid  a £1,000 fine.

You then apply for a British Citizen passport for travel and show that instead of the BRP..

Once she has been granted British citizenship, she will need her British citizen passport if she wants to travel and re-enter the UK. This year brings in the ETA which will affect citizens of all the many countries the UK used to allow to be non-visa nationals. Australia already has this system in place and you will know people will need an ETA to board a plane to the UK/enter the UK, if they don't have a British or Irish passport, or permission to be in the UK. She won't have ILR anymore.

https://www.gov.uk/government/publications/nationality-and-borders-bill-electronic-travel-authorisation-factsheet/nationality-and-borders-bill-electronic-travel-authorisation-factsheet.

https://homeofficemedia.blog.gov.uk/2024/02/01/electronic-travel-authorisation-eta-scheme-factsheet-february-2024/