As you probably know, Google News has a date search option that allows you to limit your searches to a variety of time spans, including recent items, the past 24 hours, and the past hour.

You might think, because you’re a logical and sensible person, that searching for news items from the last 24 hours would be encompass all the items found in the last hour, because of course it would, right? The last hours’ news would contain the most recent stories, so those would be at the top of a search for items found in the last 24 hours, right?

Well, no. That doesn’t appear to be correct. It looks like if you search for news found in the last hour and sort by date, you will find news stories that you will not see if you search for news in the last 24 hours and sort by date.

This might be something that everybody knows and I somehow missed it. But I was pretty surprised when I noticed it and want to make sure you know too: if you search Google News for news from the last hour you see things you will not see if you search for news from the last 24 hours.

Here’s an example. I’ll search Google News for stories with Facebook in the title, for the past hour:

Now, I will search Google News for stories with Facebook in the title again, only I’ll specify the last 24 hours instead of the last hour. And since I’m sorting my results by date, it seems logical that the first four items in my last 24 hours’ search would be the same as the first four items in the last hours’ search. But as you’ll see, they’re not.

Two stories overlap between the two searches, but that’s it. In addition, it seems like there are two news stories that maybe should have been in the last hour search but weren’t, based on the timestamps for the last-24-hours search.

It appears that Google News is applying one more filter / algorithm when you specify a search based on date. That filter, or whatever it is, is determining how many stories you see from the specified time period — and it works differently depending on the time span in which you’re searching.

I want to make it clear I’m not faulting Google for this or calling it out or whatever. It’s just the way the Google News search works. We can use these search tools better when we understand what they’re doing, even when it seems like there’s a little wonkiness going on.

Speaking of wonkiness, let me give you one more example. Let’s do a search for the last hour of Google News, limiting our search to stories that have the word potatoes in the title.

You get three results, sorted by relevance. Since there’s only three, you shouldn’t have to sort your results by date, should you? After all, all three are right there.

No, better sort by date anyway. Because then this happens:

Another story pops into the search results, and all I did was change the sorting option from relevance to date.

If you’re reading this and you use Google Alerts, you might be thinking, “Whew. Thank goodness I don’t have to bother with this nonsense because Google Alerts sends me all the news stories relevant to my search.” I… don’t know about that. I did some spot checking, searching Google News for searches I have as Google Alerts, and then seeing if they’d been sent to my email, but I found at least two examples where a story found using a search term I’m monitoring did not appear to end up in my Google Alerts. I haven’t done any rigid, thorough searching, though, so don’t take my results as gospel.

What this has taught me is that I might need to be more vigilant about searching Google News directly instead of relying on Google Alerts, and that I need to be 100% sure to use both 24-hour and past hour date searches.

If you’re searching Google News and you want to make sure you find every last story you can, be sure to play around with the various date and sorting options. You might be surprised at what you turn up!