T1 Ent Visa to ILR in 3y route.. absence rule

[ow33]

Hi,
My visa was granted: 06 Sep 2019 (date on BRP)
First Travel: 25 Sep 2019 - 26 Oct 2019 (32 days)
Second Travel: 20 Jan 2020 - 31 May 2020 (132 days)

Im looking to go for accelerated route towards ILR.. my question is about 180 absence days.. are these calculated from when visa was issued? or from date i first landed in UK? as due to flights being cancelled i was not able to travel till today and i was wondering when is the cut off time for me when i should be in UK in order to not miss the deadlines?

Any help would be appreciated.
Thanks.

[zimba]

180 days is counted on a rolling basis. You cannot have more than 180 days of absence in ANY consecutive 12 months ANYWHERE in your 5 years.