What's the visa situation in Turkey these days? I know you used to be able to stay 60 days, pop over to Greece for a day, come back, and repeat as needed. Is that still the case?
It's worth noting that in some parts of the world (including the US) there are days which are 23 hours long and others which are 25 hours long, which occur when daylight savings time starts and stops. (I'm guessing your calendar isn't high resolution enough to worry about leap seconds.) So if I'm reading your code aright, the timestamp will be off by an hour on two Sundays a year in places where DST is observed.
But to answer your original question, I'd have to say it depends. If the clever stuff is really much more efficient, or less likely to break in unusual circumstances, I say use it, but document it carefully. Otherwise, best to code it clearly.
My company made a machine for medical labs, and I wrote an app that monitored the performance of those machines. Our basic metric was samples analyzed per hour, and my app would grab the runlogs from all the machines (we needed the data in the logs for other purposes, or I'd have done the analysis on the machines and just transferred the results), count how many samples were analyzed each calendar day, and then divide by 24. Easy, simple, and worked a treat. That is, until one fine spring Monday.
The service manager walked into my office bearing the graph of machine performance, and said there was something wrong with my script. He showed me the graph, and pointed out that most of the machines had exhibited a nearly 5% drop in productivity on Sunday. This wasn't usual; the machines either worked, or they didn't, and they were expensive enough that labs generally ran them continuously. We looked at the graph for a while, and realized that the affected machines were all in the US; the ones in Asia looked normal.
This was baffling, but I did a little checking of the data, and it looked like the script was counting samples correctly. The nearly 5% drop was real.
But the next day everything was back to normal and people stopped bugging me about this, so I just let it go, though I couldn't get rid of a nagging feeling that I was missing something.
I didn't realize what it was until six months later, when those selfsame machines exhibited a nearly 5% rise in productivity, again reported to me by the service manager on a Monday. I looked at him for a moment, then said, "Not all days are 24 hours long!" I'd forgotten about daylight savings time (not observed in Asia), which makes one day in the spring only 23 hours long, and one day in the fall 25 hours long.
I fixed the calculation by using time()s, so the script'll work for any time zone. As an added bonus, even the occasional leap second is handled correctly.
Living in the developing world, as I do, net connections can be pretty flaky and certainly far from ubiquitous. As a result, things work much better for me if I can grab feeds when I have a connection and then read them offline. For me, partial feeds are a pain in the ass; give me a full feed every time. And no, I don't mind ads in my feeds.