Co-worker: “It’s 5:55.”
Me: “Do you know where your children are?”
Co-worker: 
Co-worker is about my age, so it’s not a generation gap. Mr. Rilch doesn’t remember it either. But when I was a kid, that was a ten-second TV spot, every night before the news came on. “It’s 5:55. Do you know where your children are?”
Perhaps it was only that one station. Independent, out of New York; I forget the call letters. Does anyone else remember this? And if so, what part of the country were you in?
My mom says this, though with varying times filling in for the “5:55” in your example. Mostly 11 o’clock or 8 o’clock or something later than 6 though, I think.
I remember it very well, although I thought the time in the spot was later, like 8 pm or 10 pm.
I can’t say for sure when and where I heard it, but given that I’ve been outside the US for most of the last couple of decades, I can narrow down the possibilities:
New England area, roughly 1978-82
DC area, 1982-86
Boston area, 1989-93
I’m not even from your country and I know that bit.
“It’s 10pm, do you know where your children are?”
I’m going to guess this one. I lived between DC and Baltimore from '83 to the early 90’s, and it’s ringing a bell for me.
They did it in the Orlando area at 11:00p within the last ten years, though I haven’t heard it in a while. I can’t remember which channel… six, maybe? It wasn’t a “spot” really, just a voiceover during the opening of the news show as the stations call letters flew in from the foreground resplendent in their graphical goodness.
Missed the edit window, apparently:
A Youtube search reveals some examples more recent than this.
Wikipedia puts it as far back as the 60s. I know I heard this phrase used (well, with 10PM rather than 5:55) when I was a teen - that would have been late 60s/early 70s.
It was common where I grew up, but I don’t recall it being specifically attached to 5:55.
(video link, unrelated to the OP - it just reminded me of this)
I remember it- I’m 41 and grew up in SoCal.
I still say it, although you also hear it about your parents, your husband, etc.
I remember it back when all the child abductions were taking place in Atlanta in the early 80s. Wasn’t the guy’s name Wayne Williams?
TV: Do you know where your children are?
Homer: I already told you, no!
[/Simpsons]
So anyone not knowing is inexcusable.
I’m 21 years old, by the way, and I don’t know if Australia has ever had these ads.
WNYW in New York uses this before their 10:00 news broadcast- “It’s ten pm. Do you know where your children are?” It’s currently done by a celebrity, changing each night.
North Carolinian here and I remember it well. It was played at 10 pm.
I know of this, with a 10pm punchline.
And no, I don’t live in, nor was I brought up in the U.S. How come I know about it when your co-worker doesn’t?
East coast stations and it was usually on the hour for the 10PM news.
I remember this from being a little kid in the 80s, but it never aired before 10 or 11. Then it disappeared in the 90s. One local station started it up again a few years ago right before the 11:00 news and at first I thought it was a joke. I didn’t think any TV channel still did that seriously. But apparently they do.
That was the one they used here in Houston for a long time.
[Homer Simpson]
I told you last night, NO!
Where is Bart anyway? His dinner’s getting all cold and eaten
[/HS]