"In doing business with New Zealand and Australia, we're losing out on two working days a week."
Are not they gaining two days in the 5 day week. Just like US-India, there is always somebody from the company working and available due to the 12-13 hour gap.
Your example is talking about a company having longer working hours because half of it's staff are working at any one time (maybe with some overlap).
This change is because Simoa does business with people/companies in Australasia, so they want as much time when both time zones are working as possible, not to get the longest combined amount of work time between the two zones.
That said, because they are on the International Date Line, they are moving their calendar by exactly 24 hours, so their day/night (i.e. working hours) will still have the same relationship with those in Australasia. The difference is that, after this change, they will have five weekdays that overlap with Australasia's five weekdays, whereas right now they only have three, as demonstrated in the BBC story.
Are not they gaining two days in the 5 day week. Just like US-India, there is always somebody from the company working and available due to the 12-13 hour gap.