180 Days outside uk rule for Tier 1 entrepreneur main Holder

Hi , My wife is on Tier 1 ( Entrepreneur ) visa , we have a inquiry regarding the period she can be outside the
UK from ILR Point of view after 5 years.

She has got visa in July 2016 and BRP Card was collected in London on 10th August 2016. Immediately after
collection she went to India for 3 months and was back in London on 10th November 2016.

Now she needs to plan her business trip again for couple of Months and planning to fly India in May 2017 to use her rest of the period as per 180 day rule in the 1st year.

So the Inquiry is can she use her rest of the period from the 1st year. ( balance of 180 days ) in continuation of
using next year 180 days to together.

Thanks

See also Indefinite leave to remain: calculating continuous period in UK.

Her visa was granted July 2016. So until July 2017 she can spend 180 days outside and between July 2017 to July 2018 she can spend 180 days outside and so on. 180 days per year of stay and no carry forward, so use it or lose it.
Also be aware that for you must not spend more than 450 days in total outside the UK within the last 5 years of your stay if you are aiming for UK citizenship.

Pointers:
The 'years' are counted back from day of application to ILR (you don't know for sure when you will apply it could be a few weeks/months after your 5 years are up and that could skew ur calculations (or fix a problem if cuts an 180+ year into two years)

You could be out for 359 days in a row if split among two years

Lastly we are subject to genuine entrepreneur test and one could wonder how we are running it if away for a long period (very different from many short business trips even if runs over 180 days)

There are no limitations (and not asked on extension) to days out of UK only relevant to ILR