Question about 180-day absence calculation in 12-month rolling window for ILR calculation so as to plan foreign holidays

I understand the 180-days absence rule for ILR eligibility. i.e. "the applicant should not have been absent from the UK for more than 180 days in any rolling window of 12 months during the qualifying period."

I just want to make sure I am getting the calculations right for my specific case, so that I can safely plan winter holidays outside the UK in 2021.

My only absence from the UK during my entire qualifying period has been from 12 November 2020 through 09 May 2021 (177 days, borderline case, but within the 180 days limit). I returned to the UK on May 09, 2021. I am eligible for ILR in August 2022, and don't wish to jeopardize it with some silly miscalculations in planning upcoming winter holidays outside of the UK.

If I understand correctly, in my case, I can be away for another 180 days from 13 November 2021 right? i.e. the absence allowance gets replenished on 13 November 2021 for me, right? I absolutely don't want to jeopardise my ILR application due in just a few months time Aug 2022.

No. The rolling basis calculation means that you cannot have more than 180 days’ absences are allowed in ANY consecutive 12-month period. So in theory, if you choose any RANDOM date within the 5 year period and add 12 months to that date, that is your 12-month consecutive period and you should not have more than 180 days of absence in that period.

e.g. Let's choose a date: 13/11/2020.
Your 365 days period will be from that date to 13/11/2021. In this period you cannot have more than 180 days of absence. and so on.