Strange Computer Ringing Sound at Sunset Time

[Sardon]

Hello

I'm having a very unusual issue with one of my computers where it makes a ringing sound exactly at the time the clock switches to sunset according to British Summer Time (BST). Yesterday, the ringing occurred at 20:09 BST, and today it happened at 20:11 BST.

This has only started happening in the last couple of days, and it's an old analog telephone-type ringing sound. It's really annoying and I can't figure out what's causing it.

I suspect it might be related to the Blue Iris software I have installed on one PC, but I've gone through all the sound files in the Blue Iris sound folder and there is no telephone ringing sound that resembles what is being played.

Has anyone experienced something similar with Blue Iris or know what could be causing this strange ringing at precisely sunset time? I just want to rule out if Blue Iris is the culprit or if it's something else entirely.

Any insights would be appreciated as I'm at a loss to explain this very peculiar issue.

It's very odd and it's driving me nuts!

[Pogo]

Shut down the Blue Iris service just before sunset and leave the computer running to see if the sound still occurs.

[TimG]

And watch task manager at sunset to see what pops up. Hmm, can't you record that ? Performance Monitor looks promising but I've not had to use it yet. It can save data sets.

Sunset approx 20:21 today here in the UK. Nearly time

[MikeBwca]

Point a camera straight up. Maybe you'll catch a UFO.