Long Residence: 1 month away in July = 30 or 31 days?

[dbook07]

The guidance here: http://www.ukba.homeoffice.gov.uk/sitec ... categories clearly states that

"Calculating absences from the UK
When calculating absences from the UK for long residence, a month is made up of 30 calendar days."

So if I were out of the country from 1st July to 10th August, does that count as 40 days (a month and 10 days in August) or 41 days (31 days in July and 10 days in August).

The reason I'm asking is it makes a difference to my application. I have been taking many holidays for the last 10 years. When I count the total number of "whole day" absences they come to 542 days. However, when I count a month as 30 days, plus the remaining days on that particular holiday (e.g. example above) the total comes to 533. Of course we all know the limit is 18 months (540 days).

Thanks in advance for you replies. I have already sent my application based on 533 days, I'm just a bit concerned whether they would have a case for not granting me.