The sun goes back and forth

What I expected to happen was...:
I was recording a tutorial for Minecraft when I went to check on the time. It had been around 7 minutes and I thought the sun was going to go down.

What actually happened was...:
But when I checked, the sun was still rising! I looked at it for about 10 seconds and I realised it was going up, then down. up, then down. I recorded again and the same thing happened

I think this was only Minecraft 1.13.2, but I haven't tested the other versions. I think it is only Survival, because I was playing Creative on the same version yesterday, but I made it always day so I'm not so sure. Could you please fix this QUICK so Minecrafters can enjoy Minecraft properly?

Thank You!