If you're entitled to a day off then it will be 36 hour so it covers both requirements.
The 2 FOM rules are as i said.7 days a month minimum, 36 hours in a 7 day period, or if not then a 60 hour break in 10 days.
so if you come back from leave on the 3rd say, then you only get 4 more days off that month. Each of them will involve more than 36 hours but will include a day, which is midnight to midnight..
The worst things are taking all your leave in the middle of the month, which results in no more days off that month, or splitting your leave 1 week in one month and 1 week in the next.
It wasn't always like this. Most of us were here when the 7 days off was given pro rata. but it ain't like that now.