At 0053 when I was going to bed I planned to leave the alarm set for 0600 and get about 5 hours of sleep. I know that's not enough considering I was on the sick list but as you know I need time to finish all the stuff I need to do.
But even at 0053, my alarm app dashboard was showing "Next alarm in 04:07 hours". That bewildered me, until I remembered that in 7 minutes it'd push the time one hour ahead automatically for British Summer Time adjustment. So I set the alarm to 0700 to get 5 hours of sleep.
And woke up by the alarm and got up easily. Honestly, it felt like 5 hours of biphasic quality sleep. In the day there was no sleep dep, but I did feel tired. Some of them, or most of that, would have to be attributed to my activities. It was an active day involving lots of standing, almost all day.
But still I didn't suddenly nod off or fall down around nap time. I just continued up to 2120 (getting home time), didn't even feel sleepy in the train.
Even after getting home I cooked and ate and was active on the laptop after that.
So, I think even the monophasic days in-between biphasic days are better than normal monophasic days.